JP7161231B2 - redox flow battery - Google Patents

Description

TECHNICAL FIELD The present invention relates to a redox flow battery in which an aqueous solution of vanadium sulfate can be used as an electrolyte and the degree of charge and discharge can be measured. A redox flow battery separates two types of ionic solutions with a cation exchange membrane, and charges and discharges by simultaneously advancing oxidation and reduction reactions on electrodes (made of carbon) provided in both solutions.
The overall configuration of a redox flow battery includes a positive electrode, a negative electrode, and a diaphragm interposed between these electrodes, and charges and discharges by supplying a positive electrode electrolyte and a negative electrode electrolyte.

The negative electrode electrolyte contains at least one metal ion selected from titanium ions, vanadium ions, chromium ions, and zinc ions, and the additive metal ions contained in the positive electrode electrolyte include aluminum ions, cadmium ions, and indium ions. ions, tin ions, antimony ions, iridium ions, gold ions, lead ions, bismuth ions and magnesium ions.

Specifically, the positive electrode electrolyte contains manganese ions and additional metal ions, and the negative electrode electrolyte contains at least one metal ion selected from titanium ions, vanadium ions, chromium ions, and zinc ions. The additive metal ions contained in the positive electrode electrolyte are at least one of aluminum ions, cadmium ions, indium ions, tin ions, antimony ions, iridium ions, gold ions, lead ions, bismuth ions and magnesium ions.

In addition to the metal ions exemplified above, lithium ions, beryllium ions, sodium ions, potassium ions, calcium ions, scandium ions, nickel (Ni) ions, zinc ions, gallium ions, germanium ions, rubidium ions, strontium ions, Yttrium ion, zirconium ion, niobium ion, technetium ion, rhodium ion, cesium ion, barium ion, ion of lanthanide elements (excluding cerium), hafnium ion, tantalum ion, rhenium ion, osmium ion, platinum ion, thallium ion, Polonium ions, francium ions, radium ions, actinium ions, thorium ions, protactinium ions, and uranium ions can be mentioned as additive metal ions.

The redox flow battery described in Patent Documents 1 and 2 has a liquid active material, and the battery active materials of the positive electrode and the negative electrode are circulated in a liquid-permeable electrolytic cell, and charge and discharge are performed using an oxidation-reduction reaction. is performed. It has the following advantages over other secondary batteries.
(1) To increase the amount of active material, the capacity of the storage container can be increased, and unless the output is increased, the size of the electrolytic cell itself need not be increased.
(2) The positive and negative electrode active materials can be completely separated and stored in a container, and there is little possibility of self-discharge.
(3) In the liquid permeable carbon porous electrode to be used, the charge/discharge characteristics (electrode reaction) of the active material ions are simply exchange of electrons on the electrode surface, without depositing on the electrode. The reaction of the pond is simple.

This redox flow battery consists of a diaphragm made of an ion-exchange membrane, carbon cloth electrodes (positive electrode and negative electrode) provided on both sides of the membrane, and end plates provided on the outside thereof. It is sent to the positive electrode and the negative electrode from the positive electrode electrolyte container and the negative electrode electrolyte container.

At the initial charge, tetravalent vanadium is oxidized to pentavalent vanadium at the positive electrode, tetravalent vanadium is reduced to trivalent vanadium at the negative electrode, and trivalent vanadium is reduced to divalent vanadium at the negative electrode, but the positive electrode is overcharged and oxygen is generated. produces. To avoid this, it was necessary to replace the electrolytic solution with a tetravalent vanadium solution when the positive electrode solution reached a fully charged state. In this state, when the battery is charged, the tetravalent vanadium is oxidized to pentavalent vanadium on the positive electrode side, while the trivalent vanadium is reduced to divalent vanadium on the negative electrode side. The opposite reaction will occur in the discharged state.

JP-A-5-242905 Japanese Patent Application Laid-Open No. 2018-137238

In the charged state of the redox flow battery, such as initial charge or supplementary charge to full charge, it was not particularly necessary to ensure a stable state of the electrolyte.
However, in a normal state, a positive electrode charge/discharge circuit and a negative electrode charge/discharge circuit are formed, and if the electrolytic solution does not pass through the positive electrode charge/discharge circuit and the negative electrode charge/discharge circuit, electrolysis will occur. It is also assumed that the liquid stays in the positive electrode charge/discharge circuit and the negative electrode charge/discharge circuit, and it is also assumed that the discharge start-up characteristics of the redox flow battery may deteriorate.
Also, when the output of the solar panel becomes higher than the output of the redox flow battery, the redox flow battery is charged, but unreasonable charging can lead to an unexpected temperature rise in the cell stack.

Therefore, in order to solve the conventional problems described above, it is an object of the present invention to provide a redox flow battery in which the charge/discharge start-up characteristics of the storage battery are improved and stable charging is possible.

The redox flow battery invention of claim 1 comprises a storage battery output circuit in which the DC outputs of two or more cell stacks are connected in series, and a positive electrode side electrolyte container and a negative electrode side electrolyte containing electrolytes having different characteristics. A container, a positive electrode side charging/discharging circuit and a negative electrode side charging/discharging circuit in which the flow of the electrolyte passing through the cell stack is in the same direction regardless of charging and discharging, and a positive electrode forming the flow of the electrolyte. When the output of the side liquid circulation pump and the negative side liquid circulation pump and the solar panel becomes higher than the output of the storage battery output circuit, the moving speed of the electrolyte of the positive side liquid circulation pump and the negative side liquid circulation pump is increased. It is what I did.

Here, the storage battery output circuit is formed by connecting DC outputs of two or more cell stacks in series.
The positive electrode side electrolyte container and the negative electrode side electrolyte container contain electrolytes having different characteristics.
The positive charge/discharge circuit and the negative charge/discharge circuit are charge/discharge circuits of the electrolyte in the same direction so that the flow of the electrolyte passing through the cell stack is not affected by charging and discharging.

Furthermore, the positive electrode-side liquid circulation pump and the negative electrode-side liquid circulation pump determine the flow of each of the electrolytes between the cell stack and the positive electrode-side electrolyte container, and between the cell stack and the negative electrode-side electrolyte container. It is something to do.

Furthermore, the solar panel converts light energy of sunlight into electric energy, and the inverter mainly converts the output of the solar panel from direct current to alternating current.

In addition, the voltage adjustment circuit increases the moving speed of the electrolyte in the positive electrode side liquid circulation pump and the negative electrode side liquid circulation pump when the output of the solar panel becomes higher than the output of the storage battery output circuit. is.

2. The redox flow battery according to claim 1 , wherein the voltage regulation circuit uses an aqueous solution of vanadium sulfate as the electrolytic solution, and when the electrolytic solution is "purple" or "yellow", the positive electrode side liquid circulation pump and the negative electrode side liquid circulation It slows down or stops the movement of the electrolyte in the pump.

In the redox flow battery of the invention of claim 1, the DC output of two or more cell stacks is obtained by a storage battery output circuit connected in series.
Also, when the output of the solar panel is no longer higher than the output, the electrolyte flow through the cell stack is the same regardless of charging and discharging, accommodating electrolytes with different characteristics. The positive electrode side liquid circulation pump and the negative electrode side liquid circulation pump disposed between the positive electrode side electrolyte container and the negative electrode side electrolyte container and the cell stack increase the moving speed of the electrolyte.

Therefore, the DC output from the cell stack, or two or more in series and two or more series-parallel connections, is obtained by the battery output circuit. Therefore, even if the fluid resistance of the positive electrode charge/discharge circuit and the negative electrode charge/discharge circuit is high, a short cell stack can be used. The fluid resistance passing through the charge/discharge circuit on the side and the charge/discharge circuit on the negative electrode side can be kept low, and the required electric power, that is, voltage and current can be obtained.

As a result, even if any of the cell stack faults or cell faults occur, the voltage regulation circuit will have less of an effect.
When the electrolyte is "purple" and/or "yellow", the voltage adjustment circuit slows down the moving speed of the electrolyte in the positive electrode side liquid circulation pump and the negative electrode side liquid circulation pump, and stops the charging operation. do.

In the redox flow battery of the first aspect of the invention, the voltage regulation circuit controls the electrolyte solution of the positive electrode side liquid circulation pump and the negative electrode side liquid circulation pump when the electrolyte solution is "purple" and/or "yellow". slows down or stops the movement speed of the electrolyte, in addition to the effect of claim 3, when the electrolyte becomes "purple" and/or "yellow", it means that charging is completed. Therefore, since the supply of the positive electrode side liquid circulation pump and the negative electrode side liquid circulation pump is not necessary, that is, since the charge/discharge load is simply added, it is removed from the load.

FIG. 1 is a configuration diagram explaining the principle of a redox flow battery according to an embodiment of the present invention. FIG. 2 is a configuration diagram explaining the principle of a redox flow battery of another example of the embodiment of the present invention. FIG. 3 is a configuration diagram for explaining the principle of the cell stack of the redox flow battery according to the embodiment of the present invention, (a) is a partial exploded view of the cell stack, (b) is a partial assembly diagram, and (c) is a redox flow. It is a partial assembly drawing as a battery. FIG. 4 is a configuration diagram explaining the principle of the impeller pump of the redox flow battery according to the embodiment of the present invention. FIG. 5 is an explanatory diagram illustrating the operation of the redox flow battery according to the embodiment of the present invention using one liquid circulation pump. FIG. 6 is an explanatory diagram for explaining the operation using two liquid circulation pumps of the redox flow battery according to the embodiment of the present invention. FIG. 7 is a wavelength/sensitivity characteristic diagram of “purple” and “green” and “yellow” and “blue” for explaining the principle of the redox flow battery according to the embodiment of the present invention. FIG. 8 is an explanatory diagram illustrating the principle of the color triangle used in the redox flow battery of the embodiment of the invention. FIG. 9 is an explanatory diagram illustrating an electrolytic solution distributor attached to an electrolytic solution container used in the redox flow battery according to the embodiment of the present invention. 10A and 10B are explanatory diagrams for explaining the attachment of the electrolyte solution distributor to the electrolyte solution container used in the redox flow battery according to the embodiment of the present invention. FIG. 11 is an explanatory diagram of a float sensor attached to an electrolytic solution container used in the redox flow battery according to the embodiment of the present invention. FIG. 12 is an explanatory diagram for explaining the disposition of a float sensor and an electrolytic solution distributor attached to the electrolytic solution container used in the redox flow battery according to the embodiment of the present invention. FIG. 13 is a block diagram showing control operations used in the redox flow battery of the embodiment of the invention. FIG. 14 is another example of a flowchart showing the operation of the timing circuit used in the redox flow battery of the embodiment of the invention. FIG. 15 is an explanatory diagram using a pair of electrolyte solution containers used in the redox flow battery of the embodiment of the present invention. FIG. 16 is an explanatory diagram using two pairs of electrolyte solution containers used in the redox flow battery of the embodiment of the present invention. FIG. 17 is another example of a flowchart showing the operation of the voltage regulation circuit used in the redox flow battery according to the embodiment of the invention. FIG. 18 is a block diagram of a voltage regulation circuit used in the redox flow battery of the embodiment of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In addition, in the embodiment, the same symbols and the same reference numerals in the drawings denote the same or corresponding functional parts, so redundant description thereof will be omitted here.

[Embodiment]
In FIG. 1, a known solar panel 301 is an assembly of solar cells, and although the electromotive force of one cell is small, a plurality of cells are connected in series to raise the voltage to a specific voltage. In order to charge the redox flow battery 300, a voltage is applied so as to be approximately 1.4 to 1.6 times the applied voltage of the electromotive force on the solar panel 301 side. Some have a low initial charge voltage and increase the charge voltage as charging progresses. The power that can be generated by one battery (one cell) is approximately 10 to 100 watts if one side is several tens of centimeters. A photovoltaic power generation system for residential use uses a plurality of solar panels 301, which are connected to a power conditioner via a junction box. The power generated by the solar panel 301 is consumed in the home via the inverter 304 or transmitted to other homes, and is connected to the power selling power grid according to the power selling regulations. In this case, power is supplied to the power grid. The description of the junction box of the solar panel 301 is omitted, and only the backflow prevention diodes 302 and 303 are described.

In addition, the backflow prevention diodes 302 and 303 are connected to both ends so that the redox flow battery 300 is not short-circuited by the solar panel 301 when the redox flow battery 300 is charged. The forward voltage drop of the backflow prevention diodes 302 and 303 can be ignored by increasing the electromotive force on the solar panel 301 side when charging the redox flow battery 300 .
The storage battery output circuit 501 is composed of the negative electrodes 24, 64 and the lead wires 26A and 27B, and the positive electrodes 25, 65 and the lead wires 27A and 27B.

However, the anti-backflow diodes 302 and 303 can be used to protect the solar panel 301 since they have a high reverse withstand voltage. If a power diode is used, the withstand voltage can be increased, and if n diodes are connected in series, the reverse withstand voltage can be increased by n times.

The inverter 304 is a device that converts direct current into alternating current of a predetermined frequency and voltage, and technically performs PWM modulation. Since the voltage and frequency of alternating current are difficult to convert as they are, it is necessary to first convert alternating current to direct current and then back to alternating current again. A device that converts alternating current to direct current and then back to alternating current is called an "inverter circuit" or "inverter device." It's called an "inverter". In FIG. 1, the commercial power source 305 is a single-phase 100 [V], but in the example of 100 [V] for selling power, it may be 200 [V] or other voltages.

Here, when the redox flow battery 300 is charged by the solar panel 301, the output of the solar panel 301 is transferred to the positive electrode 65 via the backflow prevention diode 302 and the lead wire 27B, and further to the negative electrode via the redox flow battery 300. Electric power is supplied through the lead wire 26A of the electrode 24 and the backflow prevention diode 303 .
Also, when the output of the solar panel 301 decreases, the backflow prevention diodes 302 and 303 are reverse biased. That is, the backflow prevention diodes 302 and 303 are turned off. At this time, the inverter 304 is connected to the lead wire 27B of the redox flow battery 300 (the suffixes A and B of 27A and 27B indicate the same function, and the suffixes A and B may be omitted if the inverter 304 has versatility). ), the lead wire 26 of the positive electrode 24 (the suffixes A and B of 26A and 26B indicate the same function, and the suffixes A and B may be omitted in some cases with general versatility). is derived and output to the commercial power supply 305 side of 50 Hz or 60 Hz.

When the remaining discharge amount of the redox flow battery 300 is low even when the solar panel 301 causes the backflow prevention diode 302 and the backflow prevention diode 303 to flow in the forward direction, first, the electric energy of the redox flow battery 300 is increased by charging. Let
In particular, the color of the electrolytic solution of the color detection unit 44 is set to "yellow" at 100%, . . . . When “green” is set to the 0% side, the redox flow battery 300 is charged from “blue” and “green” on the 0% side where the remaining amount of discharge is small.

In addition, even if the reverse current prevention diode 302 and the reverse current prevention diode 303 flow in the forward direction due to an increase in the output of the solar panel 301, the electric energy of the redox flow battery 300 is increased when the remaining discharge amount of the redox flow battery 300 is large. Since it is not necessary, for example, the color of the electrolytic solution of the color detection unit 44 is displayed in accordance with the color, so that the remaining discharge amount of the redox flow battery 300 due to charging is not increased.
In the normal state, the remaining amount of discharge is "yellow" with 100% remaining amount, and "purple" with 100% remaining amount. By setting the threshold value, the 100% is changed to 90%, 80%, or the like. be able to.
In any case, it is sufficient if the residual discharge amount of the redox flow battery 300 can be expressed numerically on the display 18 .

To summarize, the solar panel 301 for photovoltaic power generation of this embodiment, the redox flow battery 300 using the vanadium sulfate aqueous solutions 15 and 35 as electrolytes, the solar panel 301 and/or the redox flow battery 300 and an inverter 304 that converts the DC output of to AC, the electromotive force of the solar panel 301 is high, and from the cathode side of the pair of backflow prevention diodes 302 and 303 connected to the solar panel 301, the inverter 304 and the charging input of the redox flow battery 300, and when the output of the solar panel 301 becomes low, the electrical connection between the solar panel 301 and the inverter 304 and the redox flow battery 300 is cut off. is.

When the output voltage of the redox flow battery 300 is Va [V] and the output voltage of the solar panel 301 is Vb [V], the operation is performed with Va≦Vb. When a pair of backflow prevention diodes 302 and 303 are used, Va≦Vb becomes Va<Vb due to forward voltage drop of the pair of backflow prevention diodes 302 and 303 .

In the redox flow battery 300 of the present embodiment, the optical fibers 46a and 46b on the negative electrode side (the suffixes a and b of 46a and 46b indicate the same function, and those having versatility b) may be omitted), the color of the electrolytic solution in the color detection unit 44 is derived. The end portion is led from the color detection section 44 to the two color sensors 17 , and each output is output to the display 18 to indicate the remaining amount of discharge.
The usable remaining discharge capacity of the redox flow battery 300 can be indicated by the color sensor 17 at the upper end of the optical fiber 46 indicating that "yellow" indicates 90 to 100% remaining capacity and "purple" indicates 90 to 100% remaining capacity. can.
In any case, the magnitude of the remaining discharge capacity of the redox flow battery 300 can be expressed.

Based on the colors of the electrolytic solution detected by the color detection unit 44, if there is a color corresponding to either the “purple” and “green” regions or the “yellow” and “blue” regions of the electrolytic solution, the color at the upper end of the optical fiber 46 is detected. It can be detected by the sensor 17 . At this time, the numerical values of the display 18 should be the same in principle. However, there are times when the numbers are far apart. The reason for this is when a foreign substance is mixed in the electrolytic solution on the negative electrode side or the positive electrode side, and when the optical fiber 46 and the color sensor 17 are abnormal.
When the numerical value on the display 18 is greatly different, it means that the redox flow battery 300 of the present embodiment is abnormal, so it needs to be noticed and repaired as soon as possible. Even when a foreign substance enters the electrolyte, the characteristics of the redox flow battery 300 are lost, so it is necessary to repair it as soon as possible.
Of course, the display 18 consisting of the optical fiber 46 and the color sensor 17 does not match reality, so one display 18 is cheaper than two.

Therefore, when the solar panel 301 causes the forward current to flow through the anti-backflow diode 302 and the anti-backflow diode 303, the operation when the redox flow battery 300 has a large amount of discharge remaining and when the redox flow battery 300 has a small amount of discharge. For example, when the remaining amount of discharge is 60% or less, the power amount of the redox flow battery 300 is increased to 100% and then normal control is started. For example, when the color of the electrolytic solution detected by the color detection unit 44 is "yellow" 100% or less, or when the color of the electrolytic solution detected by the color detection unit 44 is "purple" 100% or less, the remaining amount of discharge becomes 100%. may do so.
In this case, the solar panel 301 forwards the backflow prevention diode 302 and the backflow prevention diode 303, and while the solar panel 301 charges the redox flow battery 300, the inverter 304 sells power to the commercial power source 305. do.

For example, when the color sensor 17 at the end of the optical fiber 46 sets the remaining amount of discharge to “yellow” as less than 100% and “purple” as less than 100%, the inverter 304 is controlled by inverter control. The input can be cut off and the redox flow battery 300 can be charged. In this case, the redox flow battery 300 is started from a 100% charged state, and only the power required for charging the redox flow battery 300 is supplied. Since the original surplus power is cut off on the inverter 304 side, the inverter 304 cannot be controlled.
In this way, between "yellow" and "purple" by the color sensor 17, the input to the inverter 304 can be cut off and the redox flow battery 300 can be started from 100% charging completion.

As shown in FIG. 1, an electrolytic solution container 11 on the negative electrode side is filled with an aqueous vanadium sulfate solution 15 . The vanadium sulfate aqueous solution 15 is circulated between the electrolyte container 11 and the cell stack 20 in which the required number of diaphragms are laminated by the liquid circulation pump 12 through the circulation line 13a, the liquid circulation pump 12, the circulation line 13b, and the circulation line 13c. It forms a circulation line for the electrolytic solution.

Similarly, the electrolytic solution container 31 on the positive electrode side is filled with a vanadium sulfate aqueous solution 35 . A vanadium sulfate aqueous solution 35 is circulated between the cell stack 20 in which the necessary number of diaphragms are laminated and the electrolytic solution container 32 by a liquid circulation pump 32 through a circulation line 33a, a liquid circulation pump 32, a circulation line 13b, and a circulation line 13c. It forms a circulating circulation pipeline.

Next, the stacking process of the cell stack 20 shown in FIGS. 3(a) to 3(c) will be described.
A single cell having a plurality of positive electrodes 102, a diaphragm 103, a negative electrode 104, a bipolar plate 105, a pair of current collector plates, a pair of cushion layers, a bipolar plate 105 formed with a metal layer, and a frame 101 attached to the outer periphery thereof. A cell stack 20 is composed of a set of (minimum unit cells).
More specifically, a pair of end plates 101 and a tightening mechanism 107 for tightening the end plates 101 are prepared. The tightening mechanism 107 is interposed between a tightening shaft 108 , nuts 110 screwed onto both ends of the tightening shaft 108 , and the nuts 110 and end plates 101 .

The entire cell stack 20 is housed in a cell stack container 120 in which air paths for fans 111 are arranged along fins functioning as heat exchangers. The cell stack container 120 is provided with a required number of cooling fans 111 for cooling the cell stack 20 so that cooling can be performed as required.
The bottom side of the cell stack 20 also has a wave structure 112 in which the cell stack container 120 is lifted from the cell stack 20 . That is, the cell stack 20 is stored in the cell stack container 120 and cooled by the cell stack 20 and the cell stack container 120 .

Then, the tightening shaft 108 and the nut 110 are attached to the end plate 101 . The end plate 101 to which the tightening shaft 108 is attached is parallel to the installation surface, a current collector plate is arranged on the end plate 101, a cushion layer is interposed thereon, and a bipolar plate 105 having a metal layer is formed. The cell frames comprising are laminated. Subsequently, single cells each composed of a positive electrode 102, a negative electrode 104, a diaphragm 104, and a negative electrode 104 (positive electrode 102) are stacked repeatedly. In this stacking step, the positive electrode 102, the diaphragm 103, and the negative electrode 104 are sequentially stacked one by one on the current collecting structure. A laminated body in which a predetermined number of cell frames, positive electrodes 102 , diaphragms 103 and negative electrodes 104 are laminated may be repeatedly placed on the current collecting structure on the end plate 101 . After stacking the desired number of cells, the cell frame having the bipolar plate 105 with the metal layer formed thereon is again joined to the last cell, and the current collector plate is stacked with the cushion layer interposed therebetween.

By forming a metal layer made of a metal material having a higher conductivity than that of the bipolar plate 105 on the bipolar plate 105, the positive electrode plate 102, the negative electrode 104, and the bipolar plate 105 can be easily connected. In addition, by interposing a flexible cushion layer between the bipolar plate 105 and the collector plate, particularly between the metal layer formed on the bipolar plate and the collector plate, even under negative pressure, A large conductive area can be secured between the metal layer and the current collector plate. Therefore, the resistance between the current collecting plate and the bipolar plate 105 can be reduced, and an increase in the resistance can be suppressed.
Since the resistance between the current collecting plate and the bipolar plate 105 can be reduced and the increase in resistance under negative pressure can be suppressed, electrical loss due to resistance, such as a decrease in battery output and a decrease in battery capacity, can be reduced. can be done. Therefore, it becomes a battery with little electric loss.

In the cell stack 20, negative electrodes and electrode plates 102 made of diaphragms are alternately arranged and connected to a negative inverter 304 by a lead wire 26A. Similarly, in the cell stack 20 , negative electrodes 24 and positive electrodes 25 composed of diaphragms 23 are alternately arranged and connected to the positive cell path 22 on the positive side by lead wires 27 .
In the cell stack 20, a negative electrode cell path 21 through which the vanadium sulfate aqueous solution 15 of the electrolytic solution container 11 circulates, and a positive electrode side cell channel 22 through which the vanadium sulfate aqueous solution 35 of the electrolytic solution container 31 is circulated are formed. 12 and a liquid circulation pump 32 connect the electrolyte container 11 or the electrolyte container 31 .

Redox flow battery 300 of the present embodiment is charged from solar panel 301 when its terminal voltage is low. More precisely, the redox flow battery 300 is charged from the solar panel 301 at a voltage equal to or higher than the output of the solar panel 301 plus twice the forward voltage drop of the backflow prevention diodes 302 and 303 .
When the terminal voltage of the redox flow battery 300 is the output voltage value of the solar panel 301, the inverter 304 converts direct current into alternating current and outputs the power to the AC generator 305 side for selling power.

At this time, if the output of the solar panel 301 decreases, the solar panel 301 is reverse biased by the backflow prevention diodes 302 and 303 , so the solar panel 301 is protected from the redox flow battery 300 . However, since the redox flow battery 300 is an input of the inverter 304, there is a possibility that the charged voltage of the redox flow battery 300 will be used.
Therefore, as shown in FIGS. 1 and 2, a backflow prevention diode 302 is connected in the forward direction to the connection point between the solar panel 301 and the inverter 304, and the side connected to the connection point between the solar panel 301 and the inverter 304 A backflow prevention diode 302 is connected in the forward direction to the lead wire 26a.

As a result, the electromotive force of the solar panel 301 is output to the inverter 304, and the redox flow battery 300 is charged when the load on the inverter 304 side is small.
Therefore, when the load of the inverter 304 is light, the electromotive force of the solar panel 301 mainly charges the redox flow battery 300 . In a normal state, the electromotive force of the solar panel 301 is output in accordance with the load of the inverter 304, and the redox flow battery 300 is charged with surplus power.
When there is no electromotive force from the solar panel 301 , such as at night, the electric discharge of the redox flow battery 300 causes an output from the inverter 304 . This output is used as a domestic load and as an external load.

1 and 2, backflow prevention diodes 302 and 303 are connected to both terminals of the solar panel 301 . Therefore, the backflow prevention diodes 302 and 303 can have a high reverse withstand voltage and can protect each cell of the solar panel 301 . The reverse current prevention diodes 302 and 303 at both ends of the redox flow battery 300 can prevent reverse connection.
This circuit has less loss because it is not affected by the forward voltage drop of the diode under normal conditions.

As the liquid circulation pumps 12, 32 and the liquid circulation pumps 12, 32, 52, 72 used in the present embodiment, Smoothflow pumps (manufactured by Takumina Co., Ltd.) are used in this embodiment. A pump Sempon, a solenoid-driven diaphragm metering pump (Sem Corporation), etc. may be used as long as the entire passage of the electrolytic solution is covered with a synthetic resin. It is sufficient that the entire liquid circulation pump function is covered with resin. In any case, the constituent material constituting the liquid feeding pump may be made of a synthetic resin such as polyethylene, polypropylene, polystyrene, nylon, polyester, etc., to feed the vanadium sulfate aqueous solution 15 or the vanadium sulfate aqueous solution 35. forming a composition.

FIG. 5 is an explanatory diagram for explaining the operation of the liquid circulation pump 12 (32, 52, 72).
The vanadium sulfate aqueous solution 15 enters the electrolytic solution container 11 from the negative electrode-side cell path 21, the liquid circulation pump 12, and the circulation conduit 13b. 61 and returns to the negative cell path 21 via the circulation conduit 13b.
Therefore, the liquid circulation pump 12 circulates the vanadium sulfate aqueous solution 15 in the negative electrode cell path 21 to form a circulation path that makes clear the difference in the "valence" of vanadium ions in the negative electrode cell path 21. .

FIG. 6 is an explanatory diagram for explaining an embodiment in which two liquid circulation pumps 12 are used.
The vanadium sulfate aqueous solution 15a in the electrolytic solution container 11a was discharged from the insertion circulation line 53a by the circulation line 13a, the liquid circulation pump 12a, and the circulation line 13b from the negative electrode cell line 21, and stirred. The vanadium sulfate aqueous solution 15 is absorbed from the conduit 61a, and is further discharged from the circulation conduit _13b1 , the liquid circulation pump 12b, and the circulation conduit _13b2 through the insertion circulation conduit 53b in the vanadium sulfate aqueous solution 15b of the electrolyte container 11b. , a liquid first circulation route and a second circulation route for absorbing the stirred vanadium sulfate aqueous solution 15 from the conduit 61b and returning to the negative electrode cell conduit 21 via the circulation conduit 13c. The vanadium sulfate aqueous solution 15 in the negative electrode cell path 21 is circulated to form a circulation path that makes clear the difference in the "valence" of vanadium ions with respect to the negative electrode cell path 21 .

A schematic diagram of the impeller pump is summarized as FIG. Alternatively, gear pumps, vane pumps, etc. may be used, and the practice of the present invention is not limited to impeller pumps.
The impeller pump has a body portion 201 containing an electric motor, a suction port 206 and a discharge port 207 attached to a flange 204 of the body portion 201, and a pump portion 209 having a flange 203 attached thereto. The impeller 208 is attached to the shaft of the electric motor of the main body 201 and rotates at the same rotation speed as the electric motor.
A seat portion 202 is arranged in the opposite direction of the discharge port 207 of the impeller 208 .
Therefore, when the electric motor inside the main body 201 rotates, centrifugal force is applied to the electrolytic solution, and the electrolytic solution flies out in the radial direction from the discharge port 207 to create a negative pressure on the suction port 206 side. The impeller pump thus functions as the liquid circulation pump 12 and the liquid circulation pump 32 .
Normally, the liquid circulation pump 12 and the liquid circulation pump 32 are used so as not to entrain air.

Here, the liquid circulation pump 12 and the liquid circulation pump 32 are set to rotate at a constant speed, and from the negative electrode cell path 21, the circulation line 13a, the liquid circulation pump 12, the circulation line 13b, the electrolyte container 11, the circulation line 13c, and the negative electrode. The side cell path 21 and the vanadium sulfate aqueous solution 15 circulate. At the same time, due to the rotation of the liquid circulation pump 32, from the positive cell line 22 to the circulation line 33a, the liquid circulation pump 22, the circulation line 33b, the electrolyte container 21, the circulation line 33c, the positive electrode side cell line 22 and the vanadium sulfate aqueous solution. 15 circulates.
At this time, the solar panel 301 charges and discharges the redox flow battery 300, and the inverter 304 supplies electric power to the power selling AC generator 305 side according to a specific program. The output of the solar panel 301 applies a negative voltage through the lead wire 26 and a positive voltage through the lead wire 27 as a predetermined DC voltage.

Further, even if two liquid circulation pumps 12 and 32 are arranged on the positive pressure side and the negative pressure side, the impeller 208 and the pump section 209 are sealed between the suction port 206 side of the impeller 208 and the discharge port 207. Since the fluid resistance is small, the fluid flow does not become difficult, and the operation can be performed with a load of 1/2.
When the two liquid circulation pumps 12 and the two liquid circulation pumps 32 are simultaneously driven, the flow rate of the electrolyte between the suction port 206 side and the discharge port 207 of the impeller 208 is doubled. Since there is a flow, it can be driven at 0.5 and 2 times the capacity. The same is true when three liquid circulation pumps 12 and three liquid circulation pumps 32 are arranged, and they can be driven with the set capacity according to need.

In FIG. 5, a circulation line 13a, one liquid circulation pump 12, a circulation line 13b, an electrolyte container 11, a circulation line 13c, a negative electrode cell line 21, and an aqueous vanadium sulfate solution 15 are circulated from the negative electrode cell line 21. do. At the same time, due to the rotation of the liquid circulation pump 32, from the positive electrode side cell container 22 to the circulation line 33a, one liquid circulation pump 32, the circulation line 33b, the electrolyte container 31, the circulation line 33c, the negative electrode side cell container 21, and so on. It shows a circulation system in which the vanadium sulfate aqueous solution 15 circulates. FIG. 5 shows the circulation of the negative electrode cell path 21, and also the circulation of the positive electrode cell container 22 (not shown).

FIG. 6 shows a circuit from the negative cell line 21 to the circulation line 13a, one liquid circulation pump 12a, the circulation line 13b, the circulation line _13b1 of the electrolytic solution container 11a, the other liquid circulation pump 12b, and the electrolytic solution. It circulates through the circulation line 13 _b2 of the container 11b, the circulation line 13c of the electrolyte container 11b, and the negative cell line 21.
Although not shown in FIG. 6, the circulation of the negative cell path 21a and the negative cell path 21b is paired with the circulation of the positive cell path 22, the positive cell path 22a and the positive cell path 22b. Eggplant.

Also, the vanadium sulfate aqueous solutions 15 and 35 change as shown in the following chemical formulas.
The positive electrode reaction is VO ²⁺ + H ₂ O →/← VO ₂ ⁺ + e ⁻ + 2H ⁺
(tetravalent (blue)) (pentavalent (yellow))
The negative electrode reaction is VO ³⁺ + e ^- →/← VO ²⁺
(Trivalent (green)) (Divalent (purple))
However, the arrow → indicates charging, and the arrow ← indicates discharging.
In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, and 75 as the electrolyte, the positive and negative electrodes can be charged and discharged by increasing or decreasing the "valence" of vanadium ions.
In this way, in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, and 75 as the electrolyte, the positive electrode and the negative electrode can be charged and discharged by increasing and decreasing the "valence" of vanadium ions. Since the vanadium aqueous solutions 15 and 35 do not deteriorate in principle, the vanadium sulfate aqueous solutions 15, 35, 55 and 75 do not deteriorate.

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, and 75 as the electrolyte, the divalent vanadium of the negative electrode is “purple”, the trivalent vanadium is “green”, and the tetravalent vanadium of the positive electrode is “blue”. ”, pentavalent vanadium is “yellow”. In the negative electrode, the divalent vanadium becomes "purple" when charging is completed, and the trivalent vanadium becomes "green" when discharging is completed. Moreover, the tetravalent vanadium of the positive electrode is "blue", and the pentavalent vanadium is "yellow". When the positive electrode is completely charged, the divalent vanadium becomes "yellow", and when the discharging is completed, the tetravalent vanadium becomes "blue".

Therefore, if this is shown by the color triangle in FIG. will be moved.
It moves on the region where the "purple" of the negative electrode's divalent vanadium and the "green" of the trivalent vanadium are connected by straight lines. It will move on the line connecting the "blue" of tetravalent vanadium of the positive electrode and the "yellow" of pentavalent vanadium. Theoretically, the color changes linearly, but it can be said that the area changes due to an error or the like.

The negative electrode used in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, and 75 as the electrolyte has divalent vanadium of “purple”, trivalent vanadium of “green”, and the positive electrode of tetravalent vanadium of “ blue”, pentavalent vanadium is “yellow”. In the negative electrode, the divalent vanadium becomes "purple" when charging is completed, and the trivalent vanadium becomes "green" when discharging is completed. Moreover, the tetravalent vanadium of the positive electrode is "blue", and the pentavalent vanadium is "yellow". When the positive electrode is completely charged, the divalent vanadium becomes "yellow", and when the discharging is completed, the tetravalent vanadium becomes "blue".

Therefore, when this is indicated by the color triangle in FIG. You would move the color on the area between "blue". It moves along the line connecting the "purple" of divalent vanadium of the negative electrode and the "green" of trivalent vanadium. It will move on the line connecting the "blue" of tetravalent vanadium of the positive electrode and the "yellow" of pentavalent vanadium.
FIG. 7 shows the relationship between wavelength and sensitivity.

As shown in the figure, the three primary colors of light are "Red (Red wavelength: 625-740 nm)", "Green (Green wavelength: 500-560 nm)", and "Blue (Blue wavelength: 445-485 nm)". In the present embodiment, the colors between "yellow" and "blue" and between "purple" and "green" are detected by the color sensor 17, so the three primary colors of light are not used for color detection. .

Therefore, the change between “yellow” and “blue” or “purple” and “green” can be regarded as a monochromatic “yellow change” or “blue change” with a wavelength of 380 to 780 [nm]. They can be detected by the color sensor 17 as a change in a single color and a change in a plurality of colors.

In addition, according to experiments by the inventors, it was confirmed that it can be realized by monochromatic detection with a wavelength of 380 to 780 [nm].
For example, the light from the lower end of the optical fiber (8φ) is guided to the input of the spectrophotometer (CM-700d; Konica Minolta Co., Ltd.) 16 so as to receive light at de: 8°. The start of charge and the completion of discharge are measured, and the reaction of the positive electrode is indicated by the color triangle in FIG. As for the current remaining amount of discharge, the value of the remaining amount of discharge exists on the line connecting "yellow" and "blue".

Note that white moves along the line connecting "yellow" and "blue". The normal remaining amount of discharge was "yellow" for charge completion and "blue" for discharge completion on the area, "yellow" was 100% capacity, and "blue" was 0% discharge remaining capacity. .
According to experiments by the inventors, a substantially proportional relationship was confirmed although the reading error was large.

The color sensor 17 as a spectrophotometer (CM-700d; Konica Minolta, Inc.) is attempted to be replaced by a circuit mounted with a color sensor (TCS34725) manufactured by Strawberry Linux (registered trademark). In addition, it was confirmed that DM-18TN manufactured by Optex FA Co., etc. can also be used if coated with a resin.
The module of the color sensor 16 equipped with the TCS34725 is designed so that the color sensor 17 does not change the color of the environment, and the white LED is installed so that the color can be distinguished even in the dark.

A white light emitting diode (LED) 45 approximates the emitted light of the reference color and prevents the surroundings of the color detection section 44 from becoming dark. In addition, the colors of the vanadium sulfate aqueous solutions 15, 35, 55, and 75 can be accurately detected by transmitted light, scattered light, or reflected light. Therefore, the electrolytic solution is easily dispersed uniformly in the vanadium sulfate aqueous solutions 15, 35, 55, 75. FIG. The lower end of the optical fiber arranged in the color detection section 44 accurately detects the colors of the vanadium sulfate aqueous solutions 15, 35, 55, 75 and the electrolytic solutions by transmitted light, scattered light, or reflected light. The upper end of the optical fiber is connected to the detection hole of a spectrophotometer (CM-700d; Konica Minolta, Inc.).

Completion of charging on the positive electrode side shown in the color triangle in FIG. The current remaining amount of discharge is on the line connecting "yellow" and "blue".
In addition, when viewed from the negative electrode side, the remaining amount of discharge is on the line connecting “purple” and “green”. % capacity, and "green" indicates 0% remaining discharge capacity.
They appear independently on the positive electrode 25 on the positive electrode side and the negative electrode 24 on the negative electrode side. However, since the positive electrode side and the negative electrode side are independent, a line connecting "yellow" and "blue" and a line connecting "purple" and "green" do not coexist. Therefore, the same information can be acquired from the two systems of the positive electrode side and the negative electrode side.
In particular, it is set so that there is a remaining amount of discharge in the line connecting "yellow" to "blue" when charging is completed on the positive electrode side, and from "purple" to "green" on the negative electrode side. can also be detected as a region by fixing a specific color.

In the present embodiment, "yellow" to "blue" and "purple" to "green" are divided into 8 or 3, and used to evaluate the remaining amount of discharge. Of course, it may be divided arbitrarily. From 'yellow' to 'blue', 'yellow' is the remaining amount of discharge that holds 100% of the charged power.
Conversely, "blue" is 0% of the remaining amount of discharge. Therefore,
100% (yellow), 90%, 80%, ..., 20%, 10%, 0% (blue), from yellow to blue, and from yellow to blue It can be divided into 10 levels, 5 levels, or the like for explanation.

"Blue (450 to 495 nm)" of tetravalent vanadium of the positive electrode, "yellow (570 to 590 nm)" of pentavalent vanadium simply the wavelength, "yellow 590 nm", "yellow 580 nm",
It can also be divided into 10 categories: "yellow 570 nm", "orange 560 nm", "orange 550 nm", "orange 540 nm", "yellow green 530 nm", "yellow green 520 nm", "yellow 510 nm", and "blue 500 nm". .

A color sensor 17 at the top of the optical fiber 46 detects three colors and has 16-bit resolution for each color.
The white LEDs (380 to 780 colors) emit light so that the colors of the vanadium sulfate aqueous solutions 15 and 35, which are the electrolytic solutions contained in the negative electrode-side electrolytic solution containers 11 and 31, can be distinguished. But I try to be able to distinguish between colors.
Since the three colors of "Red", "Green", and "Blue" of this color sensor 17 are obtained from white LEDs (380 to 780 colors), they are output from the other party. A configuration as a photocoupler is shown, and of course, it may be positively configured as a photocoupler.

Therefore, in the negative electrode, the current charge/discharge remaining amount is on the region connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium. In addition, in the positive electrode, there is a remaining amount of discharge in the amplitude at a specific wavelength presumed to be in the region connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium.
In particular, the remaining amount of discharge can be measured during charging and discharging. Therefore, if it is a normal secondary battery, it is common to measure the charge / discharge remaining amount from the charging time and the current flow, but the redox flow battery using the vanadium sulfate aqueous solution 15, 35, 55, 75 as the electrolyte 300 can measure the charge/discharge remaining capacity at that time regardless of whether the load is applied or not.

Moreover, the color of the aqueous solution of vanadium sulfate is under the region connecting the “purple” of divalent vanadium and the “green” of trivalent vanadium and the region connecting “blue” of tetravalent vanadium and “yellow” of pentavalent vanadium. is determined by color, reading errors can be reduced.
In addition, the LDE emits light at a specific frequency (white) for light emission, and the negative electrode side cell path 21 means the negative electrode side of the cell stack 20 in which the vanadium sulfate aqueous solution 15 in the electrolyte container 11 of the photodiode circulates. Then, since the specific frequency is detected, the frequency of the emission color can be detected with a small error.

In particular, when the detection of two luminescent colors is different, the detection value of the charge/discharge remaining amount with a small remaining amount of discharge is adopted, and the timing of recharging is efficiently performed.
It is detected at which wavelength 380 to 700 [nm] in one scan the color of the electrolytic solution composed of the current vanadium sulfate aqueous solution is present.
That is, the electrolytic solution of "purple (380 to 450 nm)" of divalent vanadium to "green (495 to 570 nm)" of trivalent vanadium in the negative electrode, similarly, "blue (450 to 495 nm)" of tetravalent vanadium in the positive electrode. From the pentavalent vanadium “yellow (570 to 590 nm)” electrolyte, for example, the negative electrode is divalent vanadium “purple” (380 nm) and the trivalent vanadium “green (495 nm)” or the negative electrode is divalent vanadium The region changes between “purple (450 nm)” and trivalent vanadium “green” (570 nm). At least, it suffices to have a photodetection capability to detect the color of the electrolyte solution within the range of 380 to 700 [nm]. That is, the wavelength of the electrolyte solution is 380 to 700 [nm] 100% (yellow), 90%, 80%, ..., 20%, 10%, 0% (blue)
, or may be weighted.

Thus, in the redox flow battery 300 using the vanadium sulfate aqueous solution 15, 35, 55, 75 as the electrolyte, the positive electrode and the negative electrode can be charged and discharged by increasing or decreasing the "valence" of vanadium ions. In principle, the vanadium sulfate aqueous solutions 15, 35 do not deteriorate, so the vanadium sulfate aqueous solutions 15, 35, 55, 75 do not deteriorate.
In the redox flow battery 300, the positive electrode and the negative electrode can be charged and discharged by increasing or decreasing the "valence" of vanadium ions. The aqueous solutions 15, 35, 55, 75 do not deteriorate.

Next, the electrolytic solution distributor 50 for uniformizing the ends of the electrolytic solution container 11 (31, 51, 71) will be described.
As shown in FIGS. 1 and 2 and FIGS. 9 to 12, the liquid is circulated through circulation lines 13, 33, 53, and 73, which are pipes made of synthetic resin, such as polyethylene terephthalate, which is resistant to electrolytic solutions. The pump 12 is connected to a liquid circulation pump 32 to circulate the vanadium sulfate aqueous solutions 15 and 35 electrolyte from the electrolyte containers 11 , 31 , 51 and 71 . In order to make these circulation systems uniform, the electrolytic solution distributor 50 is standardized so that it can be applied to any electrolytic solution container 11 , 31 , 51 , 71 .

Thermoplastic resins made of electrolyte-resistant materials include, for example, polyamide 46 resins belonging to engineering plastics, polyamide resins (nylon, etc.), polyacetal resins, polycarbonate resins, modified polyphenylene ether resins, polyethylene terephthalate resins, polybutylene terephthalate Resin, glass fiber reinforced polyethylene terephthalate resin, cyclic polyolefin resin, etc., polytetrafluoroethylene resin, polysulfone resin, polyethersulfone resin, amorphous polyarylate resin, liquid crystal polymer resin, which belongs to super engineering plastics (super engineering plastics) , polyether ether ketone resin, polyphenylene sulfide resin, polyamideimide resin, etc., and general-purpose resins such as polyethylene resin, polypropylene resin, polyvinyl chloride resin, polystyrene resin, polyvinyl acetate resin, ABS resin, acrylonitrile styrene resin, acrylic resin etc. These may be used alone, or may be used in combination of two or more.When such a thermoplastic resin is used, the thermoplastic resin may be added as necessary. There is a plasticizer for plasticizing.

First, the electrolytic solution distributor 50 connects the inserted circulation pipeline 53 to the circulation pipelines 13 , 33 , 53 , and 73 . Also, the circulation pipelines 13, 33, 53, 73 may be formed integrally with the inserted circulation pipeline 53 (13).
A plurality of opening holes 54 are provided in the inserted circulation pipeline 53 (13) from which the circulation pipelines 13, 33, 53, and 73 discharge. The area of the opening 54 in which the pipe line 53 is branched to prevent the pipe line 53 from descending is larger than the opening cross-sectional area of the pipe line 53 .
The insertion circulation pipeline 53 (13) connected to the electrolytic solution containers 11, 31, 51, 71 is connected using a connector, adhesive, or other connection means (not shown). Of course, packing (not shown) or the like is also used in order to improve the sealing performance. However, when carrying out the present invention, it is desirable that the electrolyte containers 11, 31, 51, 71 and the insertion circulation line 53 are integrally connected and curved as necessary.

The circulation lines 13a, 33a of the electrolytic solution distributor 50 are connected to the liquid circulation pump 12 or the liquid circulation pump 32, and from the outside of the electrolytic solution distributor 50, through the circulation lines 13a, 33a, the large-diameter line Electrolyte is circulated inside 60 from top to bottom by liquid circulation pump 12 or liquid circulation pump 32 .
That is, the circulation lines 13a and 33a pass through the upper end of the electrolytic solution distributor 50, and the electrolytic solution distributor 50, the inserted circulation line 53, the lines 81, and the lines 82 (13b) are integrated by the synthetic resin pipe. formed. The length of the electrolyte distributor 50 is preferably in the range of 7/10 to 10/10, preferably 8/10 to 9/10, of the length ratio of the electrolyte containers 11 and 31 .
Also, the length of the electrolyte distributor 50 is desirably in the range of 1/10 to 5/10, preferably 2/10 to 4/10. Electrolyte distributor 50, pipeline 81 (13b), and pipeline 82 (13b) are integrally formed of a synthetic resin tube.

The conduit 81 (13b) and conduit 82 (13b) of the electrolyte distributor 50 are formed as a circulation conduit 13c, and the lower end of the conduit 81 (13b) extends from the electrolyte distributor 50 to the electrolyte container 11, 31, more specifically, the electrolytic solution moves from the lower pipeline 81 (13b) to the pipeline 82 (13b).
A filter 84 is used for removing dust and breathing vanadium sulfate aqueous solutions 15, 35, 55, and 75. FIG. The fastener 51 of the electrolytic solution distributor 50 has an elastic packing, an elastic filter, and a sealing structure to prevent leakage of the machining liquid in order to firmly fix it to the electrolytic solution containers 11, 31, 51, and 71. FIG. It can be firmly attached to the electrolytic solution containers 11 , 31 , 51 and 71 by the fasteners 81 .
A color detector 44 is formed below the electrolytic solution distributor 50, and a white LED 45 is fixed to one surface of a substrate 48 thereof. The white LED 45 has a substrate whose entire surface is molded with a synthetic resin.

Next, the operation of the electrolyte distributor 50 will be described.
The electrolyte in the transparent large-diameter tubular body 52 of the electrolyte distributor 50 connected to the liquid circulation pumps 12, 32, 52, 72 is delivered from the liquid circulation pumps 12, 32, 52, 72, 13a, 33a, through the insertion circulation conduit 53, through the opening hole 54 drilled in the insertion circulation conduit 53, flow into the transparent large-diameter tubular body 52, become the rectifying section 49, and are supplied to the color detecting section 44. be done. In the color detection section 44, the white LED 45 is electrically led to which the electrolytic solution rectified by the rectification section 49 is supplied, and the color detection section 44 outputs a predetermined color. The color detector 44 detects the internal light of the color detector 44 from the end of the optical fiber 46 as transmitted light, scattered light, or reflected light.

The rectifying portion 49 allows the flow of the electrolytic solution to flow without partially disturbing it, and a known shape can be used. In addition, the internal light of the color detection unit 44 is detected as transmitted light, scattered light or reflected light from the end of the optical fiber 46 by the flow rate of the vanadium sulfate aqueous solution 15, 35, 55, 75 flowing through the color detection unit 44, and color detection is performed. When optical fiber 46 detects transmitted, scattered, or reflected light at section 44, the adhesive-fixed tip of optical fiber 46 can detect only color by defocusing without special focus adjustment. I'm trying Further, by making the inside of the color detection unit 44 white, it is possible to clearly distinguish between transmitted light, scattered light, and reflected light.

An end member 89 is integrally joined to the lower end side of the large-diameter transparent large-diameter tubular body 92 with a synthetic resin by a known means. A rectifying portion 49 through which the electrolytic solution flows is formed as a slit on the bottom surface thereof. An end member 89 is formed in the lower portion of the insertion circulation pipe 53 (13a), and a passage for the electrolytic solution is formed in a state in which a plurality of opening holes 54 are provided. That is, the electrolytic solution sent from the liquid circulation pump 12 and the liquid circulation pump 32 descends through the insertion circulation pipeline 53, exits the insertion circulation pipeline 53 through the plurality of openings 54, and reaches the transparent large-diameter tubular body 92. It enters, descends through the slit 57 and is detected by the white LED 55 and the tip of the optical fiber 46 .

When DM-18TN or the like manufactured by Optex FA Co., Ltd. is used as the color sensor 17, a photocoupler consisting of a white LED 55 and three photodiodes (not shown) of "red", "blue", and "green" , 380 to 700 [nm], and has a light detection capability to detect the color of the electrolyte.
In the present embodiment, it is actually measured by Sekonic Spectromaster C-7000, and from the “purple” of divalent vanadium in the negative electrode to the “green” of trivalent vanadium, similarly, the “blue” of tetravalent vanadium in the positive electrode to the pentavalent vanadium 'yellow' is measured, and between 'purple' and 'green' and 'blue' and 'yellow' are measured, and discharge and charge are divided into 3-20.

Thus, discharging and charging are divided into 3-20 equal scales. That is, the value of the remaining amount of discharge detected by the color sensor 17 is divided into 3-20.
Although the remaining discharge amount of the redox flow battery 300 may be directly displayed on the display 18, it is usually sufficient to express the electric power required for operation numerically. It would be nice if it could be set in steps. In particular, since it is difficult for a situation in which charging is required to occur, it may be finely set to 20 steps or more. However, its importance is not high.

In this embodiment, the liquid circulation pumps 12, 32, 52, 72 may be entirely covered with synthetic resin, and only the pump function may be entirely covered with resin or rubber. may be
One unit for circulation of the electrolyte solution from "purple" of divalent vanadium to "green" of trivalent vanadium in the negative electrode, and one unit for circulation of the electrolyte solution from "blue" of tetravalent vanadium to "yellow" of vanadium pentavalent in the cathode. Requires a platform, measures between its ``purple'' and ``green'' and ``blue'' and ``yellow'', discharges and charges from ``purple'' to ``green'' and ``blue'' to ``yellow'' As previously mentioned, it can be divided into 3-20 ratings.
Therefore, at least two liquid circulation pumps 12, 32, 52, 72 are required. In any case, the number of liquid circulation pumps 12 and liquid circulation pumps 32 is an even number when two or four are added. If this is seen in pairs, it will be one or more pairs.

Next, the float sensor 100 will be explained.
The electrolytic solution container 11 on the negative electrode side is filled with an aqueous vanadium sulfate solution 15, and the electrolytic solution container 31 on the positive electrode side is filled with an aqueous vanadium sulfate solution 35. As shown in FIG. A float sensor 100 for detecting the liquid levels of the electrolytic solution container 11 and the electrolytic solution container 31 and knowing the liquid level of the electrolytic solution in the electrolytic solution container 11 and the electrolytic solution container 31 accommodates vanadium sulfate aqueous solutions 15, 35, 55, and 75. are disposed in the electrolyte containers 11, 31, 51, 71. The float sensor 100 is fastened to the electrolytic solution containers 11 , 31 , 51 , 71 by a screw portion 126 formed on the float sensor 100 .
The float sensor 100 has a center moving rod 121 arranged in the center, and a float 123 moves up and down around the center moving rod 121 . A permanent magnet is embedded in the float 123, and a float sensor 100 comprising a reed switch 124 embedded in the center moving rod 121 is provided.
The guide tube 125 prevents the float 123 from colliding with the periphery of the center moving rod 121 when the float 123 moves up and down.

Therefore, the electrolytic solution container 11, 31, 51, 71 on the positive electrode side is attached to the mounting hole of the center moving rod 121 provided on the top plate from the upper surface of the container containing the vanadium sulfate aqueous solution 15, 35, 55, 75. The float sensor 100 is a float sensor 100 made of foamed synthetic resin in which a reed switch 124 is embedded. There is a surface, and the float sensor 100 outputs an on/off signal at a predetermined liquid level.
The water level sensor knob 128 is for screwing the electrolytic solution containers 11, 31, 51, 71 on the negative electrode side and the electrolytic solution containers 11, 31, 51, 71 on the positive electrode side. It is for respiration of the fluctuating water level of the electrolytic solution container 11 or the electrolytic solution container 31 on the positive electrode side.
Further, in the present embodiment, the float sensor 100 is provided separately from the electrolyte distributor 50, but the float sensor 100 can be assembled to the electrolyte distributor 50 when implementing the present invention. For example, the float 123 may be attached to the insertion circulation line 93 ( 13 a ) and the line 81 ( 13 b ), or the float sensor 100 may be provided inside the electrolytic solution distributor 50 .

FIG. 9 shows that the electrolytic solution distributor 50 is firmly fastened to the electrolytic solution container 11 of the negative electrode side cell path 21 and the electrolytic solution container 31 of the positive electrode side cell 22, and the electrolyte solution container 11 and the electrolytic solution container 31 are also provided with float sensors. 100 is screwed tightly. At this time, if necessary, rubber packing or the like is used to perform bonding with good sealing performance. Therefore, the electrolytic solution container 11 and the electrolytic solution container 31 are connected to the liquid circulation pumps 12 and 32, and two circulation pipes 13 or 33 are provided for the electrolytic solution container 11 and the electrolytic solution container 31. It is

A single optical fiber 46 and a lead wire 97 of the float sensor 100 are drawn out, and the signal of the color sensor 17, the liquid circulation pump 12, and the liquid circulation pump 32 are connected to a controller (CPU). .

Electrolyte containers 11, 31, 51 and 71 are formed with handles 19a and 19b, respectively, so that they are movable. The electrolytic solution container 11 of the negative electrode cell path 21 and the electrolytic solution container 31 of the positive electrode cell 22 are paired. The electrolytic solution container 11 and the electrolytic solution container 31 circulate the electrolytic solution in the cell stack 20 divided into the negative electrode side cell path 21 and the positive electrode side cell path 22 .

At this time, one liquid circulation pump 12 and one liquid circulation pump 32 were arranged, but as described above, two or more of each may be arranged in series. Of course, one or more liquid circulating pumps may be provided to uniformly expand sales of the vanadium sulfate aqueous solution 15 and the vanadium sulfate aqueous solution 35 .

For example, as shown in FIG. 13, the liquid circulation pumps 12, 32, 52, and 72 may be paired as a pair of the electrolytic solution container 11 of the negative electrode side cell channel 21 and the electrolytic solution container 31 of the positive electrode side cell channel 22, As shown in FIG. 14, two pairs of the electrolyte container 11 of the negative cell channel 21 and the electrolyte container 31 of the positive electrode cell channel 22 are provided as one pair, or three or four pairs (not shown) are provided. can also be provided.

In the present embodiment, the electrolyte distributor 50, the float sensor 90, and the electrolyte containers 11 and 31 are standardized, so the standardized redox flow battery 300 can be formed by selecting the battery housing main body 400.
FIG. 13 is an illustration of arranging the float sensor 100 and the electrolyte distributor 50 mounted on the electrolyte containers 11, 31, 51, and 71 used in the redox flow battery 300 of the embodiment of the present invention on the frame. It is a diagram.
The battery frame 401 of the battery housing main body 400 is formed by molding a metal rod with a square cross section with a synthetic resin, and the material is selected so as not to be corroded by acid. Container spaces 402 and 403 into which the electrolytic solution container 11 or the electrolytic solution container 31 can be freely inserted are integrated inside the battery frame 401, and a controller storage space 404 is also integrated. 403 and the controller storage space 404 are integrated, and if the electrolyte leaks up to a position 1/3 to 2/3 of the height of the electrolyte container 11 and the electrolyte container 31, A container in which container spaces 402 and 403 and a controller storage space 404 are integrated prevents liquid leakage.

Further, the container integrated with the container spaces 402 and 403 and the controller storage space 404 of the present embodiment is blow-molded using a synthetic resin film or the like. You may shape so that the lower part of the space 404 may be connected.
A space for storing the negative cell path 21 is formed above the controller storage space 404, and the cell stack 20 is connected thereto.
In the present embodiment, the upper portion of the controller housing space 404 constitutes a controller for the electrolyte with the space for housing the cell stack 40B and the rear surface of the lid 406 .

A controller CPU consisting of a microcomputer and its control lines are provided on the upper surface of the lid 206, and the liquid circulation pumps 12 and 32 shown in FIG. 15 and respective pipes are provided on the lower surface.
For example, the lead wire of the white LED of the electrolytic solution distributor 50, the lead wire of the float sensor 100, the container spaces 402 and 403, and the controller storage space 404 are integrated into a humidity sensor, a water leak sensor, a water sensor, or the like. It is connected to the microcomputer CPU. In addition, whether or not it is operating normally, whether it is being charged, or whether it is being discharged, etc. are displayed.

In FIG. 13, one electrolyte container 11 and one electrolyte container 31 are provided, and the electrolyte containers 11 and 31 are basically two pairs of a positive electrode and a negative electrode, and have the same shape. The number of parts is reduced. In FIG. 14, two electrolytic solution containers 11 and two electrolytic solution containers 31 are used. is reduced.
A feature of this embodiment is that one electrolytic solution container 11, 31 can be used several times. Other configurations are not different from FIG. It shows that one electrolyte solution container 11, 31 can be increased by 4 times, 6 times, 8 times, . . .

14, two electrolyte containers 11 and two electrolyte containers 31 are provided.
Of course, the negative electrode side circulates through the negative electrode cell line 21, the circulation line 13a, the liquid circulation pump 12, the circulation line 13b, the vanadium sulfate aqueous solution 15, the circulation line 13c, and the positive electrode cell line 21. Go back to 21. On the positive electrode side, the positive electrode cell line 22, the circulation line 33a, the liquid circulation pump 32, the circulation line 33b, the vanadium sulfate aqueous solution 35, the circulation line 33c, and the negative electrode cell line 21 are connected in series with the liquid circulation pump 32. , and return to the positive cell path 22 is added.

At this time, the outlet of the aqueous vanadium sulfate solution 15 of the negative electrode cell path 21 and the outlet of the aqueous vanadium sulfate solution 35 of the positive electrode cell path 22 may be located at the same end, or both outlets of the aqueous vanadium sulfate solution 15 of the negative electrode cell path 21 may be located at the same end. It can be the opposite end.

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15 and 35 in the present embodiment as an electrolyte, while changing tetravalent vanadium to pentavalent vanadium by charging or changing pentavalent vanadium to tetravalent vanadium by discharging, and/or a positive electrode side charge/discharge state detection unit that detects the color of the electrolytic solution composed of tetravalent vanadium and pentavalent vanadium with a color sensor 17 and specifies the charge state of the positive electrode of the electrolytic solution from the color, While changing the valence vanadium to divalent vanadium or while changing the divalent vanadium to trivalent vanadium by charging, and / or detecting the color of the electrolytic solution composed of divalent vanadium and trivalent vanadium with the color sensor 17, A negative electrode side charge/discharge state detection unit that identifies the charge state of the negative electrode of the electrolytic solution from the color, and the positive electrode side charge/discharge state detection unit and/or the negative electrode side charge/discharge state detection unit detects circulation of the electrolytic solution. The wavelength (frequency) of the remaining discharge is calculated from the detected value of one or more of transmitted light, scattered light, and reflected light of the LED arranged in the pipe, and the remaining discharge is calculated from the wavelength (frequency). Identify.

The positive electrode reaction is VO ²⁺ + H ₂ O →/← VO ₂ ⁺ + e ^- + 2H ⁺
(tetravalent (blue)) (pentavalent (yellow))
The negative electrode reaction is VO ³⁺ + e ⁻ →/← VO ²⁺
(Trivalent (green)) (Divalent (purple))
However, the arrow → indicates charging, and the arrow ← indicates discharging.
In the redox flow battery 300 using the vanadium sulfate aqueous solution 15, 35, 55, 75 as the electrolyte, the positive electrode and the negative electrode can be charged and discharged by increasing and decreasing the number of "valences" of vanadium ions. Since the aqueous solution does not deteriorate in principle, the vanadium sulfate aqueous solution 15, 35, 55, 75 does not deteriorate.

In the redox flow battery 300 using the vanadium sulfate aqueous solution 15, 35, 55, 75 as the electrolyte, the divalent vanadium of the negative electrode is “purple”, the trivalent vanadium is “green”, and the tetravalent vanadium of the positive electrode is “blue”. ”, pentavalent vanadium is “yellow”. In the negative electrode, the divalent vanadium becomes "purple" when charging is completed, and the trivalent vanadium becomes "green" when discharging is completed. Moreover, the tetravalent vanadium of the positive electrode is "blue", and the pentavalent vanadium is "yellow". When the positive electrode is completely charged, the divalent vanadium becomes "yellow", and when the discharging is completed, the tetravalent vanadium becomes "blue".

Therefore, if this is shown by the color triangle in FIG. 8, the tetravalent vanadium of the positive electrode changes between "blue (450 to 495 nm)" and the pentavalent vanadium changes between "yellow (570 to 590 nm)". It will move the color on the area between "yellow" and "blue".
Similarly, the divalent vanadium of the negative electrode is "purple (380-450 nm)", the trivalent vanadium is "green (495-570 nm)", the pentavalent vanadium is "yellow", and the trivalent vanadium is "green". It will move the color over the area. It moves on the region connecting the positive electrode's tetravalent vanadium "blue" and pentavalent vanadium "yellow".

The divalent vanadium of the negative electrode used in the redox flow battery 300 using the vanadium sulfate aqueous solution 15, 35, 55, 75 as the electrolyte is “purple (380 to 450 nm)”, the trivalent vanadium is “green (495 to 570 nm)”, The tetravalent vanadium of the positive electrode is "blue (450 to 495 nm)", and the pentavalent vanadium is "yellow (570 to 590 nm)". In the negative electrode, the divalent vanadium becomes "purple" when charging is completed, and the trivalent vanadium becomes "green" when discharging is completed. Moreover, the tetravalent vanadium of the positive electrode is "blue", and the pentavalent vanadium is "yellow". When the positive electrode is completely charged, the divalent vanadium becomes "yellow", and when the discharging is completed, the tetravalent vanadium becomes "blue".

Therefore, when this is shown by the color triangle in FIG. You would move the color on the area between "blue".
It moves on the area connecting the negative electrode's "purple" color of divalent vanadium and "green" color of trivalent vanadium. It will move on the line connecting the "blue" of tetravalent vanadium of the positive electrode and the "yellow" of pentavalent vanadium.

A wavelength of a frequency including 380 to 700 [nm] is output from the white LED that constitutes the light emitting element. Since the peak of the output of the light-receiving element for emitted light with a specific wavelength of 380-700 [nm] is at any of the specific wavelengths of 380-700 [nm], the peak value at the negative electrode is 2 From "purple (380 to 450 nm)" of valent vanadium to "green (495 to 570 nm)" of trivalent vanadium, and in the positive electrode, "blue (450 to 495 nm)" of tetravalent vanadium to "yellow ( 570-590 nm)”.
Therefore, in the negative electrode, the current remaining amount of charge and discharge is on the region connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium. In addition, in the positive electrode, it can be seen that there is a remaining amount of charge and discharge in the amplitude at a specific wavelength presumed to be in the region connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium.

In particular, the charge/discharge remaining amount can be measured even during charging and discharging. Therefore, if it is a normal secondary battery, it is common to measure the charge / discharge remaining amount from the charging time and the current flow, but the redox flow battery using the vanadium sulfate aqueous solution 15, 35, 55, 75 as the electrolyte In 300, if the load of the redox flow battery 300 is applied, regardless of whether it is not applied, the charge/discharge remaining amount at that time can be measured.
Moreover, the color of the vanadium sulfate aqueous solution can be discriminated in the area connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium, and the area connecting the blue of tetravalent vanadium and the "yellow" of pentavalent vanadium. Therefore, it is judged by color, and reading error can be reduced.
In addition, since the LDE emits light at a specific frequency and the photodiode constituting the photocoupler detects the specific frequency, the frequency of the emitted light can be sharply detected.

In particular, when the remaining discharge amounts of the two luminescent colors are different, the detection value of the remaining discharge amount that reduces the remaining charge amount is adopted, and the timing of recharging is efficiently performed.
For example, the current color of the electrolytic solution made of vanadium sulfate aqueous solution is detected in one scan of about 380 to 700 [nm].
That is, the electrolytic solution of "purple (380 to 450 nm)" of divalent vanadium to "green (495 to 570 nm)" of trivalent vanadium in the negative electrode, similarly, "blue (450 to 495 nm)" of tetravalent vanadium in the positive electrode. From the pentavalent vanadium “yellow (570 to 590 nm)” electrolyte, for example, the negative electrode is divalent vanadium “purple (380 nm)” and the trivalent vanadium “green (495 nm)” or the negative electrode is divalent vanadium The region changes between "purple (450 nm)" and "green (570 nm)" of trivalent vanadium. At least, it suffices to have a photodetection capability to detect the color of the electrolyte solution within the range of 380 to 700 [nm].

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, and 75 according to the present embodiment as the electrolyte solution, during charging to change tetravalent vanadium to pentavalent vanadium or discharging to change pentavalent vanadium to tetravalent vanadium While changing and/or detecting the color of the electrolytic solution composed of tetravalent vanadium and pentavalent vanadium with the color sensor 17, detecting the positive electrode side discharge remaining amount to specify the charge state of the positive electrode of the electrolytic solution from the color part, while changing trivalent vanadium to divalent vanadium by discharging or changing divalent vanadium to trivalent vanadium by charging, and/or changing the color of the electrolyte solution composed of divalent vanadium and trivalent vanadium A detection unit on the negative electrode side that detects the charge state of the negative electrode of the electrolytic solution from the color detected by the sensor 17, and a detection unit for the remaining discharge amount on the positive electrode side and/or the remaining discharge amount on the negative electrode side. The detection unit calculates the wavelength (frequency) of the remaining amount of discharge from the detected values of transmitted light, scattered light, and reflected light of a light-emitting diode arranged in the circulation pipe of the electrolyte, and detects the wavelength (frequency). The smaller value is specified as the charge power amount.

In the redox flow battery 300 that uses the vanadium sulfate aqueous solutions 15, 35, 55, and 75 of this embodiment as the electrolyte, the detection unit for the remaining discharge amount on the positive electrode side and/or the detection unit for the remaining discharge amount on the negative electrode side The wavelength (frequency) of the residual discharge is calculated from the detected value of transmitted light or reflected light arranged in the liquid circulation pipes 13, 33, 53, 73, and the smaller detected value of the wavelength (frequency) is used. It was identified as the remaining amount of discharge.
In the redox flow battery 300 using the vanadium sulfate aqueous solution 15, 35, 55, 75 as the electrolyte, the positive electrode and the negative electrode can be charged and discharged by increasing and decreasing the number of "valences" of vanadium ions. Since the aqueous solutions 15, 35, 55, 75 are not degraded in principle, the vanadium sulfate aqueous solutions 15, 35, 55, 75 are less likely to be degraded.

Further, in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15 and 35 as the electrolyte, the above-mentioned 4 A positive electrode side charge/discharge state detection unit that detects the color of an electrolytic solution composed of valent vanadium and pentavalent vanadium with a color sensor 17 and specifies the charge state of the positive electrode of the electrolytic solution from the color, and a trivalent vanadium by discharging to 2 During the change to valent vanadium or while the divalent vanadium is changed to trivalent vanadium by charging, the color of the electrolytic solution composed of the divalent vanadium and the trivalent vanadium is detected by the color sensor 17, and the color of the electrolytic solution is detected from the color. The negative electrode side charge/discharge state detection unit that specifies the charge state of the negative electrode detects the wavelength (frequency) of the charge power amount based on the peak value of the transmitted light or reflection of the light emitting diode arranged in the circulation pipe of the electrolyte. , the current charging status can be accurately known.

In the redox flow battery 300 using the vanadium sulfate aqueous solution 15, 35, 55, 75 as the electrolyte, the detection of the remaining discharge amount on the positive electrode side and/or the detection of the remaining discharge amount on the negative electrode side is performed by the electrolyte circulation tube. Based on the peak value of transmitted light or reflected light of the light emitting diodes arranged on the paths 13 and 33, the smaller of the detection value of the remaining discharge amount on the positive electrode side or the detection unit of the remaining discharge amount on the negative electrode side is taken as the charging power amount. Since the calculation is performed, the voltage does not drop abnormally during use of the battery.

In addition, since the charge power amount is calculated based on the color of the electrolyte solution, the switching timing of the spare electrolyte solution containers (11, 31, 51, 71) is clarified, and a plurality of spare electrolyte solution containers can be switched. Switching can be performed accurately.
In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, and 75 of the present embodiment as the electrolyte, the circulation conduit of the electrolyte in the positive electrode side charge/discharge state detection unit and/or the negative electrode side charge/discharge state detection unit Scattered light or reflected light from the white light emitting diodes 45 arranged at 13, 33, 53, and 73 is detected by the current vanadium sulfate aqueous solution. The color of the electrolyte consisting of 15, 35, 55, and 75 is detected at which of 380 to 700 scanning [nm].

That is, the electrolytic solution of "purple (380 to 450 nm)" of divalent vanadium to "green (495 to 570 nm)" of trivalent vanadium in the negative electrode, similarly, "blue (450 to 495 nm)" of tetravalent vanadium in the positive electrode. From the pentavalent vanadium “yellow (570 to 590 nm)” electrolyte, for example, the negative electrode is divalent vanadium “purple (380 nm)” and the trivalent vanadium “green (495 nm)” or the negative electrode is divalent vanadium The region changes between "purple (450 nm)" and "green (570 nm)" of trivalent vanadium. At least, it suffices to have a photodetection capability to detect the color of the electrolyte solution within the range of 380 to 700 [nm].

In the redox flow battery 300 using the vanadium sulfate aqueous solution 15, 35, 55, 75 of the present embodiment as the electrolyte, circulation of the electrolyte in detection of the remaining discharge amount on the positive electrode side and/or detection of the remaining discharge amount on the negative electrode side The detection value of the remaining amount of discharge on the negative electrode side of the white LED arranged in the pipe line 13, 33, 53, 73 is that the vanadium sulfate aqueous solution 15, 35, 55, 75 is the "purple (380 to 450 nm) of the electrolytic solution. ” and “green (495 to 570 nm)”, or any position connecting “blue (450 to 495 nm)” and “yellow (570 to 590 nm)”. is calculated.

At this time, the remaining amount of discharge obtained from the region from "purple (380 to 450 nm)" to "green" (495 to 570 nm), and from the region from "blue" (450 to 495 nm) to "yellow (570 to 590 nm)" The obtained remaining amount of discharge may be simply averaged to obtain the remaining amount of discharge of the electrolytic solution, or the amount of electric power with a small or large amount of discharge from the remaining amount of discharge may be selected.
In any case, the difference between the two decreases during repeated use, so there is no big difference between the two.

FIG. 15 shows an example of a redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, and 75 of the present embodiment as electrolyte solutions, and only differences from FIG. 1 or 2 will be described.
The liquid circulation pump 12 rotates at a constant speed, and the electrolytic solution container 11 containing the vanadium sulfate aqueous solution 15 through the circulation line 13b, the negative electrode side cell line 21 of the cell stack 21 through the circulation line 13c, and the circulation line 13d. through the negative electrode side cell path 21 in order.
Similarly, the liquid circulation pump 32 rotates at a constant speed. , rotates the negative cell path 21 of the cell stack 20 via the circulation path 33c.

Here, the circulation line 13a, the liquid circulation pump 12, the circulation line 13b, the electrolyte container 11 in which the vanadium sulfate aqueous solution 15 in the electrolyte container 11 circulates from the negative electrode cell line 21, the negative electrode cell line 21, and the negative electrode cell. 21, the negative electrode side cell line 21, the circulation line of the circulation line 13d, and from the positive electrode side cell line 22, the circulation line 33a, the liquid circulation pump 32, the circulation line 33b, and the vanadium sulfate aqueous solution 35 of the electrolytic solution container 31. circulates through the electrolyte container 31, the positive electrode cell path 22, and the circulation conduit 33d.
In this embodiment, the number of liquid circulation pumps 12, 32, 52, 72 is not increased.

In this way, the cell stacks 20, 60 have independent circulation lines for the vanadium sulfate aqueous solutions 15, 35, 55, 75, and separate the vanadium sulfate aqueous solutions 15, 35, 55, 75 from each other. By increasing the capacity of the electrolyte container 11 and the electrolyte container 31 of 35, 55, 75, the output time can be lengthened.
By serially connecting the cell stacks 20, 60 in the circular direction, the output voltage can be determined. The voltage of the cell stacks 20, 60 is determined by the positive electrode 25 and the negative electrode 24 sandwiching the diaphragm plate 23B, and the area of the positive electrode 25 and the negative electrode 24 determines the rated current.

That is, in FIG. 15, the area of the positive electrode plate 25 and the negative electrode plate 25 on the cell stack 20A side is the same as the area of the positive electrode plate 25 and the negative electrode plate 25 on the cell stack 20A side, and the rated energization is performed. The power consumption on the cell stack 20 side is increased without changing the current.
The electric power of the cell stack 20, the cell stack 20A, and the cell stack 20B is the electric power of the control device of the redox flow battery 300 that uses the vanadium sulfate aqueous solutions 15 and 35 of the present embodiment as the electrolytic solution while the cell stack 20A consumes a small amount of power. is to be used.

When carrying out the present invention, it is not always necessary to separate the cell stack 20 and the cell stack 60, but if the configuration of the cell stack 60 is added to the configuration of the cell stack 20 as in this embodiment, vanadium sulfate The aqueous solutions 15, 35, 55, and 75 circulate as electrolytes, and the number of charge/discharge times and reuse of the electrolytes do not change. will not be.
In particular, if the electric power for controlling the redox flow battery 300 of the present embodiment is used from the cell stack 60 side, deterioration of the cell stack 20 can be reduced.
Although the output voltage V1 of the cell stack 20 and the output voltage V2 of the cell stack 60 have a relationship of V1=V2, V1≧V2 and V1≦V2 can also be satisfied.
It is also possible to vary their rated currents.

The cell stack 20 and the cell stack 60 in the case of carrying out the present invention are evaluated by observing the change in the electromotive force of the redox flow battery 300 and the change in the electromotive force of the redox flow battery 300 at the completion of charging. It is for understanding the difference between
In particular, the vanadium sulfate aqueous solutions 15, 35, 55, and 75 of the redox flow battery 300 circulate as electrolyte, and the number of charge/discharge times and the reuse of the electrolyte do not change, so the cell stacks 20 and 60 are in a proportional relationship. Become. However, the characteristics of a secondary battery such as the redox flow battery 300 can be changed depending on the power used.

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, and 75 of the present embodiment as the electrolyte, Detection by transmitted light, scattered light, or reflected light of the white LEDs 45 arranged in the circulation pipes 13, 33, 53, 73 is detection of the remaining discharge amount on the positive electrode side and/or detection of the remaining discharge amount on the negative electrode side. The detection value of the part is "purple (380 to 450 nm)" and "green (495 to 570 nm)", "blue (450 to 495 nm)" and "yellow (570 to 590 nm)" of the vanadium sulfate aqueous solution 15 and 35 of the electrolytic solution. , and from the charging and discharging characteristics of the cells arranged in the electrolytic solution circulation lines 15, 35, 55, 75 of the vanadium sulfate aqueous solution 15, 35, 55, 75, the residual discharge is detected. The amount may be calculated and corrected accordingly.

FIG. 13 illustrates the control configuration of the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, and 75 of the present embodiment as electrolyte solutions.
Redox flow battery 300, solar panel 301, inverter 304, and commercial power supply 305 are the same as in FIGS.

Although not shown, the controller CPU has a required number of humidity sensors for detecting electrolyte leakage from the electrolyte containers 11, 31, 51, and 71 and leakage from the cell stack 20 to the cell stack container 120. Binary output is input.

Also, the required number of float sensors 100 are used as binary inputs for the control device CPU. The output for lighting the required number of white LEDs 45 and the detection output of the required number of color sensors 17 are output from the control device CPU. Further, the remaining discharge amount of the redox flow battery 300 is displayed on the display 18, and the display objects are divided into 3 to 20. FIG. As for the liquid circulation pumps 12, 32, 52, 72, power is supplied to the required number of pairs of liquid circulation pumps 12, 32, 52, 72 as well. In this embodiment, charging and discharging are normally performed by rotating at 100% electric power. Also, when charging and discharging are small, charging and discharging are performed at a rotation speed of 1/3 to 1/10.

The redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the present embodiment as the electrolyte is controlled as shown in the flowchart of FIG.
First, in step S0, initialization is performed, and in step S1, it is determined whether or not the vanadium sulfate aqueous solution 15, 35, 55, 75 is leaking by the humidity sensor. The positive and negative terminals of the redox flow battery 300 using 15, 35, 55, and 75 as an electrolyte are opened to stop charging and discharging from the redox flow battery 300, and in step S3, the display 18 is flashed or one side or Repeat tumbles with red on both sides. That is, it complains of an abnormal stop state.
At this time, the color sensor 17 does not act at all. When the humidity sensor operates, the routine processing of steps S0 to S3 is repeatedly executed.

When it is determined in step S1 that the vanadium sulfate aqueous solution 15, 35, 55, 75 has not leaked from the humidity sensor, the color sensor 17 in step S4 causes the display 18 to light up numerical values or colors in step S5, and the vanadium sulfate aqueous solution is detected. 15, 35, 55, and 75 remaining discharge levels are detected. Specifically, the remaining amount of discharge is calculated from the color detected by the color sensor 17, and the remaining amount of discharge is displayed on the display 18 in step S6.
The indication that the display 18 lights up numerical values or colors is confirmation data during use of the redox flow battery 300 .
It is determined whether the value of the float sensor 100 in step S7 is within a predetermined range (the range sandwiched between a high value and a low value). , the rotational speed of the liquid circulation pump 12 is reduced.

Conversely, when the value of the float sensor 100 is lower than the predetermined liquid level, the rotational speeds of the liquid circulation pumps 12, 32, 52, 72 are increased. The speed is similarly controlled in steps S7 and S8. At this time, the liquid circulating pumps 12, 32, 52, 72 may be continuously variable, or may be speed-changeable in several stages.
At step S9, it is determined whether or not the liquid circulation pumps 12, 32, 52, 72 are stopped. determine whether The duration of T time may be a minimum unit of 24 hours, 48 hours, or 72 hours. If the liquid circulation pumps 12, 32, 52, and 72 have not been operated continuously for the T time period, the liquid circulation pumps 12, 32, 52, and 72 are driven continuously for the t time period in step S11 in order to avoid disturbance in the characteristics of each cell.

When the liquid circulation pumps 12, 32, 52, 72 are driven and continuously operated for t time in step S11, and when the remaining amount of discharge is 100% in step S12, further charging is impossible. At S13, the operation of the liquid circulation pumps 12, 32, 52, 72 is slowed down or stopped.
When the discharge load of the redox flow battery 300 is small in step S14, or when the charge load of the redox flow battery 300 is small, the liquid circulation pumps 12 and 32 are discharged in step S16 when the charging current or discharging current is small. , 52 and 72 are reduced to about 1/2 to 1/10. At least vanadium sulfate aqueous solutions 15, 35, 55 and 75 are circulated.

Also, in steps S14 and S16, the vanadium sulfate aqueous solutions 15, 35, 55, and 75 are used as the electrolytic solution of the redox flow battery 300, but when the discharge load of the redox flow battery 300 is large, When the charging current or discharging current is large, the current of the liquid circulation pumps 12, 32, 52, 72 is increased to 100% in step S15 so that the vanadium sulfate aqueous solution 15, 35, 55, 75 can function as an electrolyte. is circulated to
Of course, in step S14, when the charge/discharge load of the redox flow battery 300 is large and when it is small, it is divided into two. It is good, and you may make it correspond continuously.

In the redox flow battery 300 that uses the vanadium sulfate aqueous solutions 15, 35, 55, and 75 of the above embodiments as the electrolyte solution, while the tetravalent vanadium is changed to the pentavalent vanadium by charging, or the pentavalent vanadium is changed to the tetravalent vanadium by discharging. While changing to , the color of the electrolytic solution composed of tetravalent vanadium and pentavalent vanadium is detected by the color sensor 17, and the charge state of the positive electrode of the electrolytic solution is specified from the color. Detecting the remaining discharge amount on the positive electrode side and , While the trivalent vanadium is changed to divalent vanadium by discharging or while the divalent vanadium is changed to trivalent vanadium by charging, the color of the electrolyte composed of the divalent vanadium and the trivalent vanadium is detected by the color sensor 17. , and detection of the remaining discharge amount on the negative electrode side for specifying the state of charge of the negative electrode of the electrolytic solution from the color, and the detection of the remaining discharge amount on the positive electrode side and/or the detection of the remaining discharge amount on the negative electrode side. , the remaining amount of discharge is calculated from any one or more detected values of transmitted light, scattered light, and reflected light of the white LED 45 of the color detection unit disposed in the electrolyte circulation line.

In the redox flow battery 300 using the vanadium sulfate aqueous solution 15, 35, 55, 75 as the electrolyte, the positive electrode and the negative electrode can be charged and discharged by increasing and decreasing the "valence" of vanadium ions. Since the aqueous solutions 15, 35, 55 and 75 are theoretically not degraded, the electrolytic solution is not degraded.
In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, and 75 as the electrolyte, the divalent vanadium of the negative electrode is “purple”, the trivalent vanadium is “green”, and the tetravalent vanadium of the positive electrode is “blue”. ”, pentavalent vanadium is “yellow”.
In the negative electrode, the divalent vanadium becomes "purple" when charging is completed, and the trivalent vanadium becomes "green" when discharging is completed. Moreover, the tetravalent vanadium of the positive electrode is "blue", and the pentavalent vanadium is "yellow". When the positive electrode is completely charged, the divalent vanadium becomes "yellow", and when the discharging is completed, the tetravalent vanadium becomes "blue".

Just in case, this is indicated by the color triangle in FIG. , and moves along a line connecting the negative electrode's divalent vanadium (purple) and trivalent vanadium (green). In principle, it moves along the line connecting the positive electrode's tetravalent vanadium "blue" and pentavalent vanadium "yellow". However, even if the error is taken into account, it will move on the area connecting the positive electrode "blue" and "yellow".

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, and 75 as the electrolyte, the divalent vanadium of the negative electrode is “purple”, the trivalent vanadium is “green”, and the tetravalent vanadium of the positive electrode is “blue”. ”, pentavalent vanadium is “yellow”. Divalent vanadium becomes "purple" when charging of the negative electrode is completed, and trivalent vanadium becomes "green" when discharging is completed. Moreover, the tetravalent vanadium of the positive electrode is "blue", and the pentavalent vanadium is "yellow". When the positive electrode is completely charged, the divalent vanadium becomes "yellow", and when the discharging is completed, the tetravalent vanadium becomes "blue".

Therefore, the tetravalent vanadium of the positive electrode becomes "blue", and the pentavalent vanadium becomes "yellow", moving in the color region between "yellow" and "blue" shown in FIG.
It moves on the area connecting the negative electrode's "purple" color of divalent vanadium and "green" color of trivalent vanadium. It moves on the region connecting the positive electrode's tetravalent vanadium "blue" and pentavalent vanadium "yellow".

Therefore, the light emitting element is caused to emit light of a specific wavelength, and the photodiode that constitutes the light receiving element selects from the peak value of the output of the light receiving element, from the "purple" of divalent vanadium to the "green" of trivalent vanadium at the negative electrode. , or from the "blue" of tetravalent vanadium to the "yellow" of pentavalent vanadium at the positive electrode.
Therefore, in the negative electrode, the current charge/discharge remaining amount can be detected on the region connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium. In addition, in the positive electrode, it can be seen that there is a charge/discharge remaining amount at a specific wavelength presumed to be on the region connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium.

In particular, it is possible to measure the charge/discharge remaining amount without turning off the power during charging or discharging. Therefore, in the case of a normal secondary battery, the charging time can generally be calculated from the charging time and the energized current. Whether the redox flow battery 300 is under load or not under load, the charge/discharge remaining amount at that time can be measured.
Moreover, the lines connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium, the lines connecting the blue of tetravalent vanadium and the "yellow" of pentavalent vanadium, the vanadium sulfate aqueous solution 15, 35, 55 , 75, it is determined by color, and reading errors can be reduced.
In addition, since the LDE emits light at a specific frequency and the photodiode constituting the photocoupler detects the specific frequency, the frequency of the emission color can be accurately detected.

If the remaining discharge amount of the negative electrode and the positive electrode differ depending on the two colors, the detected value of the remaining discharge amount with the small remaining charge amount may be used as the detection value, or the detection value of the remaining discharge amount may be used. An average value may be given. Alternatively, the power side with the larger detected value of the remaining amount of discharge may be used as the detected value.
That is, it detects at which wavelength the color of the current electrolytic solution composed of the vanadium sulfate aqueous solutions 15, 35, 55, and 75 is, and if there is an error, the "purple" of divalent vanadium in the negative electrode is changed to that of trivalent vanadium. The “green” electrolytic solution, similarly, the “blue” of tetravalent vanadium in the positive electrode to the “yellow” electrolytic solution of pentavalent vanadium, for example, the negative electrode is “purple” of divalent vanadium and “green” or the negative electrode will change between "purple" of divalent vanadium and "green" of trivalent vanadium. At least, it suffices to have a light detection capability for detecting which color the electrolyte is in.

Here, when the remaining amount of discharge, which is the least amount of remaining charge, is used as the detection value, both are matched by repeated charging. In addition, whether the average value of the detected values of the remaining discharge amount is obtained or the detected value of the large detected value of the remaining discharge amount is used as the detection value, both can be matched by repeated charging. That is, even if the detected value varies in magnitude due to fluctuations in the load, a steady state in which the positive electrode and the negative electrode are balanced can be achieved by continuously performing charging and discharging.

The detection of the remaining discharge amount on the positive electrode side and/or the detection of the remaining discharge amount on the negative electrode side is performed by disposing a color detection unit 44 in each of the electrolytic solution circulation lines 13, 33, 53, 73. By transmitted light, scattered light, and reflected light of the provided white LED 45, it is detected whether or not there is a remaining amount of discharge between the initial charging of the positive electrode and/or the negative electrode or the supplementary charge and the full charge.
Detection of the remaining discharge amount on the positive electrode side and/or detection of the remaining discharge amount on the negative electrode side of the redox flow battery 300 using the vanadium sulfate aqueous solution 15, 35, 55, 75 as the electrolyte is performed by the electrolyte circulation line 13, 33, 53, and 73 are provided with color detection units 44, and the transmitted light, scattered light, and reflected light of the white LEDs 45 provided there are used to detect the initial charging of the positive electrode and/or the negative electrode, or the period from supplementary charge to full charge. Detects whether there is a remaining amount of discharge.
Since the color detection unit 44 is arranged in the circulation lines 13, 33, 53, 73 of the electrolytic solution, the vanadium sulfate aqueous solution 15, 35, 55, 75 does not stagnate. Accurately judge colors.

In the redox flow battery 300 using the vanadium sulfate aqueous solution 15, 35, 55, 75 of the present embodiment as the electrolyte, circulation of the electrolyte in detection of the remaining discharge amount on the positive electrode side and/or detection of the remaining discharge amount on the negative electrode side Detection by transmitted light, scattered light, or reflected light of the white LEDs arranged in the pipes 13, 33, 53, 73 is a detection value for detecting the remaining discharge amount on the positive electrode side and/or detecting the remaining discharge amount on the negative electrode side. detects whether the vanadium sulfate aqueous solution 15, 35, 55, 75 is in the "purple" or "green" region or the "blue" or "yellow" region of the electrolyte, and the circulation line of the electrolyte 13, 33, 53, and 73 are specified from the charge/discharge characteristics of some or all of the redox flow batteries 300, and the remaining amount of discharge is calculated.

For example, the average value or the minimum value or the maximum value is detected in which of the "purple" to "green" region and the "blue" to "yellow" region from initial charging or supplementary charging to full charging. , from the charge/discharge characteristics of part or all of the secondary battery, for example, the redox flow battery 300, disposed in the electrolyte circulation line, with respect to the remaining discharge amount consisting of the average value, minimum value, or maximum value thereof It specifies and calculates the remaining amount of discharge.

Further, from the perspective of the redox flow battery structure, when the output voltage of the redox flow battery 300 is Va [V] and the output voltage of the solar panel 301 is Vb [V], operation is performed with Va≦Vb. When a pair of backflow prevention diodes 302 and 303 are used, Va≦Vb becomes Va<Vb due to forward voltage drop of the pair of backflow prevention diodes 302 and 303 .
And this is a solar panel 301 for photovoltaic power generation of the embodiment, a redox flow battery 300 using vanadium sulfate aqueous solution 15, 35, 55, 75 as an electrolyte, the solar panel 301 and / or the redox flow and an inverter 304 that converts the DC output of the battery 300 to AC, the electromotive force of the solar panel 301 is high, and from the cathode side of the pair of backflow prevention diodes 302 and 303 connected to the solar panel 301 When the input of the inverter 304 and the charging input of the redox flow battery 300 are obtained, and the output of the solar panel 301 becomes low, the electrical connection between the solar panel 301 and the inverter 304 and the redox flow battery 300 is cut off. It is something to do.

The solar panel 301 for photovoltaic power generation of this embodiment, the redox flow battery 300 using the vanadium sulfate aqueous solution 15, 35, 55, 75 as an electrolyte, and the solar panel 301 and/or the redox flow battery 300 and an inverter 304 for converting DC output to AC. When the electromotive force of the solar panel 301 includes a forward voltage drop and Va≤Vb, a pair of backflow prevention connected to the solar panel 301 is provided. The input of the inverter 304 and the charging input of the redox flow battery 300 are obtained from a pair of cathode sides of the diodes 302 and 303 for the inverter.
When the output of the solar panel 301 becomes low, the electrical connection between the solar panel 301 and the inverter 304 and the redox flow battery 300 is cut off. At this time, the output of the redox flow battery 300 is taken out as the output of the inverter 304, but since the load of the commercial power supply 305 becomes light at night, the power can be supplied from the redox flow battery 300 at night according to its capacity.
Moreover, when the capacity of the redox flow battery 300 is large, the electric power can be sold to an electric power company.

The above embodiment consists of the flow of the electrolyte consisting of the tetravalent vanadium and the pentavalent vanadium during the change of the tetravalent vanadium to the pentavalent vanadium by charging or the change of the pentavalent vanadium to the tetravalent vanadium by discharging. A charging/discharging circulation path 13, 33, 53, 73 consisting of circulation paths 33, 33a, 33b, 33c on the positive electrode side, and while changing trivalent vanadium to divalent vanadium by discharging or changing divalent vanadium to trivalent vanadium by charging Vanadium sulfate aqueous solution 15, 35 having a charging and discharging circuit consisting of the negative electrode side circulation pipes 13, 13a, 13b, 13c consisting of the flow of the electrolytic solution consisting of the divalent vanadium and trivalent vanadium during conversion to vanadium , 55, 75 in the redox flow battery 300 as an electrolyte, the liquid circulation pumps 12, 32, 52, 72 for circulating the electrolyte are sent out and the electrolyte is diffused. Electrolyte solution containers 11, 31, 51, 71 containing a cylindrical body composed of a tubular body 52 and a cylindrical body composed of the transparent large-diameter tubular body 52; It is arranged in parallel with the cylindrical body composed of the transparent large-diameter tubular body 52 for discharging the electrolyte in the electrolyte containers 11, 31 to the outside of the electrolyte containers 11, 31, 51, 71 by the pressure of the liquid. and an exhaust pipe.

The redox flow battery 300 using the vanadium sulfate aqueous solution 15, 35, 55, 75 of the present invention as an electrolyte has positive electrode-side circulation lines 33, 33a, 33b formed by the flow of the electrolyte containing tetravalent vanadium and pentavalent vanadium. , 33c is an electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium while the tetravalent vanadium is changed to the pentavalent vanadium by charging or the pentavalent vanadium is changed to the tetravalent vanadium by discharging. It consists of the flow of
In addition, charging/discharging circulation paths 13, 33, 53, and 73, which are composed of the circulation paths 13, 13a, 13b, and 13c on the negative electrode side, which are composed of electrolyte solutions composed of divalent vanadium and trivalent vanadium, discharge trivalent vanadium. is changed to divalent vanadium or the divalent vanadium is changed to trivalent vanadium by charging.

That is, the charging/discharging circuit consisting of the positive electrode side circulation pipes 33, 33a, 33b, and 33c forms a positive electrode as a secondary battery, and is a terminal for extracting current. The charging/discharging circulation path composed of the circulation paths 13, 13a, 13b, and 13c on the negative electrode side forms a negative electrode as a secondary battery, and is a terminal into which current flows. The charge/discharge circuits on the positive electrode side and the negative electrode side include the independent positive electrode side circulation lines 33, 33a, 33b, and 33c, and the negative electrode side circulation lines 13, 13a, 13b, and 13c. A charging/discharging circulation path is formed, and an electromotive force is generated by the electrolyte flowing therethrough.

The cylindrical body made of the transparent large-diameter tube 52 and the electrolytic solution containers 11, 31, 51, and 71 containing the cylindrical body made of the transparent large-diameter tube 52 are provided with liquid circulation pumps 12 and 71 for circulating the electrolytic solution. The electrolytic solution sent from 32, 52, 72 is diffused so as to be evenly distributed. is.
Furthermore, the discharge pipes 61 and 62 discharge the electrolyte in the electrolyte containers 11 and 31 to the outside of the electrolyte containers 11 and 31 by the pressure of the electrolyte sent from the liquid circulation pumps 12 and 32 . , to circulate in the cell stack via a pipe line, and a method of arranging in parallel with the cylindrical body composed of the transparent large-diameter tubular body 52 is preferable.

In particular, the charging/discharging circulation path consisting of the circulation paths 33, 33a, 33b, and 33c on the positive electrode side of the redox flow battery 300 using the vanadium sulfate aqueous solutions 15 and 35 as the electrolyte converts tetravalent vanadium to pentavalent vanadium by charging. An electrolyte solution consisting of said tetravalent vanadium and pentavalent vanadium during the conversion or during the conversion of the pentavalent vanadium to tetravalent vanadium by electrical discharge. In addition, the charging/discharging circuit consisting of the negative electrode side circulation pipes 13, 13a, 13b, and 13c has a of said divalent vanadium and trivalent vanadium electrolyte streams.
A cylindrical body composed of a transparent large-diameter tubular body 52 for circulating and diffusing the electrolytic solution delivered from the liquid circulation pumps 12, 32, 52, 72 and a cylindrical body composed of the transparent large-diameter tubular body 52 are accommodated. The electrolytic solution containers 11, 31, 51, and 71 are configured so that the electrolytic solution in the electrolytic solution containers 11 and 31 is pushed out by the pressure of the electrolytic solution sent from the liquid circulation pumps 12 and 32. , 51, 71 to the cell stacks 20, 60.

Therefore, the electrolyte delivered from the liquid circulation pumps 12, 32, 52, 72 circulates through the electrolyte containers 11, 31, 51, 71 delivered from the liquid circulation pumps 12, 32, 52, 72. Then, the electrolytic solution circulating in the cylindrical body composed of the transparent large-diameter tubular body 52 and the electrolyte container 11, 31, 51, 71 accommodating the cylindrical body composed of the transparent large-diameter tubular body 52 is diffused. Therefore, the electrolytes in the electrolyte containers 11, 31, 51, 71 circulating in the cell stacks 20, 60 are uniformly distributed as vanadium having different valences.
Further, the electrolytic solution sent from the liquid circulation pumps 12, 32, 52, 72 is passed through the electrolytic solution containers 11, 31, 51, 71 that accommodate the cylindrical bodies and the cylindrical bodies that are double stacked. becomes a complicated flow, vanadium with different valences is well mixed, and as a result of circulating it as the electrolyte, the electrolyte in the electrolyte containers 11, 31, 51, and 71 circulates in the cell stack 20. is uniformly distributed, and the electromotive force of the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, and 75 as electrolytes is stabilized.

The liquid circulation pumps 12, 32, 52, 72 for circulating the electrolytic solution of the redox flow battery 300 of the above-described embodiment are attached so as to be accommodated in the upper part of the tubular body composed of the transparent large-diameter tubular body 52. .
Here, the liquid circulation pumps 12, 32, 52, and 72 for circulating the electrolytic solution of the redox flow battery 300 are accommodated in the upper portion of the cylinder formed of the transparent large-diameter tube 52, and the transparent large-diameter tube 52 By integrating it with the upper part of the tubular body made of the transparent large-diameter tubular body 52, the outer shape can be made to be the size of the tubular body made of the transparent large-diameter tubular body 52. As shown in FIG.

The liquid circulation pumps 12, 32, 52, 72 for circulating the electrolytic solution of the redox flow battery 300 are attached to be accommodated in the upper part of the cylinder, so that the cylinder formed of the transparent large-diameter tube 52 is installed. Since the liquid circulation pumps 12, 32, 52, 72 to be accommodated in the upper part of the body are attached, the liquid circulation pumps 12, 32, 52, 72 are accommodated in the upper part of the cylindrical body composed of the transparent large-diameter tubular body 52. Then, various parts can be accommodated in the cylindrical body composed of the transparent large-diameter tubular body 52, and parts can be replaced in units of the cylindrical body composed of the transparent large-diameter tubular body 52 in the event of a failure.

The color sensor 17 detects the color of the electrolytic solution under the LED lighting that determines the color of the electrolytic solution of the redox flow battery 300 of the present invention and the white LED 45, and the LED lighting is a surrounding light source. Therefore, white is preferred, but other colors may be used. The color sensor 17 is for judging the color of the electrolytic solution, and it is sufficient if the color can be judged as well as the lightness and darkness.
Since the redox flow battery 300 of the present invention is equipped with LED lighting composed of white LEDs 45 that determine the color of the electrolyte and the color sensor 17 that detects the color of the electrolyte under the LED lighting, the redox flow battery Since the color of the electrolytic solution of 300 is detected by the LED lighting and the color sensor 17 under the LED lighting, it is not affected by the depth of the electrolytic solution and is not affected by the number of years of use. There is no need for maintenance because it does not receive.

In addition, the redox flow battery 300 of the present invention further includes a float sensor 100 for detecting the liquid level position of the electrolytic solution in the cylinder made of the transparent large-diameter tubular body 52 . It was established.
Here, since the float sensor 100 operates at a predetermined liquid level, it can be operated by two sensors, a humidity sensor, a water level sensor, or the like.
In the redox flow battery 300 of the present invention, the float sensor 100 for detecting the liquid surface position of the electrolytic solution in the cylinder is further provided in the cylinder composed of the transparent large-diameter tubular body 52. Since the float sensor 100 can be managed by a tubular body or a tubular body made of a tubular body having a rectangular cross section and can be moved in the managed state, the trouble of protecting it with a cushioning material or the like can be saved.

In addition, since the redox flow battery 300 of the present invention further has a breathing hole and a filter 84 attached to the upper portion of the tubular body composed of the transparent large-diameter tubular body 52, the electrolyte does not react to changes in the outside temperature. is offset by the volume changes of the electrolyte containers 11, 31, 51, and 71, the change is less than the original amount of change in breathing air. Also, the amount of air passing through the filter 84 changes little, and dust and the like are not drawn in.
Furthermore, a breathing hole and a filter 84 are assembled in the upper part of the tubular body composed of the transparent large-diameter tubular body 52 .
Here, the breathing hole in the upper part of the cylinder made of the transparent large-diameter tubular body 52 is not limited to the upper surface of the tubular body made of the transparent large-diameter tubular body 52. good. Further, the filter 84 preferably does not absorb moisture of the electrolytic solution, and by repelling the liquid, a liquid blocking effect can be obtained.

The electrolyte liquid circulation pumps 12, 32, 52, 72 are arranged on the upper plane side formed by the electrolyte containers 11, 31, 51, 71 as a whole.
Here, the upper plane side formed by the entire electrolytic solution container 11, 31, 51, 71 means the plane on the plane of the upper surface of the electrolytic solution container 11, 31, 51, 71 or the back surface thereof. The liquid circulation pumps 12, 32, 52, and 72 can be installed in the upper flat position or in the lower position. position. In particular, it may be located at a position where it is easy to replace parts as a movable part.
Since the liquid circulation pumps 12, 32, 52, 72 of the redox flow battery 300 of the present invention are disposed on the upper plane side formed by the electrolyte containers 11, 31, 51, 71 as a whole, Since it is arranged on the upper surface side formed by the entirety of the electrolytic solution containers 11, 31, 51 and 71, maintenance can be performed freely and workability can be improved.

A storage battery output circuit 501 comprising lead wires 26A, 26B and lead wires 27A, 27B connecting the DC outputs of two or more cell stacks in series, and a positive electrode side electrolyte container 35 containing electrolytes having different characteristics, 75 and the negative electrode side electrolyte containers 15 and 55, and the positive electrode side charging/discharging circulation paths 33 and 73 and the negative electrode side in which the electrolyte flows through the cell stacks 20 and 60 in the same direction regardless of charging and discharging. charging/discharging circulation paths 13 and 53, and the electrolytes are respectively connected to the cell stacks 20 and 60 and the positive electrode side electrolyte containers 33 and 73, or the cell stacks 20 and 60 and the negative electrode side electrolyte containers 13 and 53; the positive liquid circulation pumps 32, 72 and the negative liquid circulation pumps 12, 52 that determine the flow between and a time limit circuit 502 consisting of steps S9 to S11 for creating a flow of the electrolyte for a predetermined time when the stop time is exceeded.
The storage battery output circuit 501 means the DC circuit indicated by the thick black solid line in FIGS. 1 and 2 .

In redox flow battery 300 of the present embodiment, DC outputs of two or more cell stacks 20 and 60 are obtained by series-connected storage battery output circuit 501 .
The same positive electrode side charging/discharging circuits 33, 73 and negative electrode side charging/discharging circuits 13, 53 are connected to the same cell stack 20 without being affected by charging and discharging of the electrolyte flowing through the cell stacks 20, 60. , 60, positive electrode side electrolyte containers 31 and 71 containing electrolyte solutions having different characteristics from those of 60; 52, when the set continuous stop time T of the positive electrode side liquid circulation pumps 32, 72 and the negative electrode side liquid circulation pumps 12, 52 is exceeded in the time limit circuit 502, the electrolyte flow is formed for a predetermined time t. It is something to do.

Therefore, the DC output from the cell stacks 20 and 60 or two or more series and two or more series-parallel connections are obtained by the storage battery output circuit 501 . Therefore, even if the fluid resistance of the positive charge/discharge circuits 33, 73 and the negative charge/discharge circuits 13, 53 is high, the short cell stacks 20, 60 can be used. can be ensured, and the fluid resistance passing through the positive electrode side charging/discharging circuits 33, 73 and the negative electrode side charging/discharging circuits 13, 53 can be kept low. can be taken out.

Here, when the set continuous stop time of the positive electrode side liquid circulation pumps 32, 72 and the negative electrode side liquid circulation pumps 12, 52 is exceeded, the cell stack 20 may be , 60 may not rise sharply. Therefore, the time limit circuit 502 causes the fluid passing through the positive electrode side charge/discharge circuits 33 and 73 and the negative electrode side charge/discharge circuits 13 and 53 to The side liquid circulation pumps 12, 52 are operated. As a result, even if some cell stack 20, 60 or cell failure occurs, the timing circuit makes it difficult for the effect to occur.

The timer circuit 502 slows down the moving speed of the electrolyte of the positive electrode side liquid circulation pumps 32, 72 and the negative electrode side liquid circulation pumps 12, 52 when the electrolyte is "purple" and/or "yellow". It is a thing.
Therefore, when the electrolyte is 'purple' and/or 'yellow', it means that charging is completed, and the operation is stopped at that point.
The time limit circuit 502 can be a timer circuit that sets a long time limit T, such as a specific day unit, and a timer that sets a short long time limit t, such as a specific time unit. .

In addition, in the redox flow battery 300 of the present embodiment, the DC outputs of the two or more 20 and 60 are obtained by the storage battery output circuit 501 connected in series.
Then, when the output of the solar panel 301 is no longer higher than the output of the storage battery output circuit 502, the flow of electrolyte passing through the cell stacks 20, 60 is the same regardless of charging and discharging, and the characteristics are different. The positive electrode side liquid circulation pumps 32 and 72 and the negative electrode side liquid circulation pumps disposed between the positive electrode side electrolyte containers 31 and 71 and the negative electrode side electrolyte containers 11 and 51 and the cell stacks 20 and 60 which contain the electrolyte to 12 and 52 slow down the movement speed of the electrolyte or stop the movement.

Therefore, the DC output from the cell stacks 20 and 60 or two or more series and two or more series-parallel connections are obtained by the storage battery output circuit 501 . Therefore, even if the fluid resistance of the positive charge/discharge circuits 33, 73 and the negative charge/discharge circuits 13, 53 is high, the short cell stacks 20, 60 can be used. A DC voltage can be secured, and the fluid resistance passing through the positive charge/discharge circuits 33, 73 and the negative charge/discharge circuits 13, 53 can be kept low, and the required power, that is, voltage and current, can be reduced. I can take it out.

That is, the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, and 75 of the present embodiment as the electrolyte is controlled as shown in the flowchart of FIG.
First, in step S0, initialization is performed, and in step S1, it is determined whether or not the vanadium sulfate aqueous solution 15, 35, 55, 75 is leaking by the humidity sensor. The positive and negative terminals of the redox flow battery 300 using 15, 35, 55, and 75 as an electrolyte are opened to stop charging and discharging from the redox flow battery 300, and in step S3, the display 18 is flashed or one side or Repeat tumbles with red on both sides. That is, it complains of an abnormal stop state.
At this time, the color sensor 17 does not act at all. When the humidity sensor operates, the routine processing of steps S0 to S3 is repeatedly executed.

When it is determined in step S1 that the vanadium sulfate aqueous solution 15, 35, 55, 75 has not leaked out from the humidity sensor, in step S4 the color sensor 17 causes the display 18 to light up numerical values or colors in step S5, and the vanadium sulfate aqueous solution 15, 35, 55, and 75 remaining discharge levels are detected. Specifically, the remaining amount of discharge is calculated from the color detected by the color sensor 17, and the remaining amount of discharge is displayed on the display 18 in step S6.
The indication that the display 18 lights up numerical values or colors is confirmation data during use of the redox flow battery 300 .
It is determined whether the value of the float sensor 100 in step S7 is within a predetermined range (the range sandwiched between a high value and a low value). , the rotation speed of the liquid circulation pump 12 is reduced.

Conversely, when the value of the float sensor 100 is lower than the predetermined liquid level, the rotational speeds of the liquid circulation pumps 12, 32, 52, 72 are increased. The speed is similarly controlled in steps S7 and S8. At this time, the liquid circulation pumps 12, 32, 52, 72 may be continuously variable, or may be speed-changeable in several stages.
In step S9, it is determined whether or not the liquid circulation pumps 12, 32, 52, 72 are stopped. determine whether The duration of T time may be a minimum unit of 24 hours, 48 hours, or 72 hours. If the liquid circulating pumps 12, 32, 52, and 72 have not been operated continuously for the time T, the liquid circulating pumps 12, 32, 52, and 72 are driven continuously for the time t in step S11 in order to prevent disturbance of the characteristics of each cell.

When the liquid circulation pumps 12, 32, 52, and 72 are driven and continuously operated for t time in step S11, and the remaining amount of discharge is 100% in step S12, further charging is impossible. In S13, the operation of the liquid circulation pumps 12, 32, 52, 72 is slowed down or stopped.
When the discharge load of the redox flow battery 300 is small in step S14, or when the charge load of the redox flow battery 300 is small, the liquid circulation pumps 12 and 32 are discharged in step S16 when the charging current or discharging current is small. , 52 and 72 are reduced to about 1/2 to 1/10. At least vanadium sulfate aqueous solutions 15, 35, 55 and 75 are circulated.

Also, in steps S14 and S16, the vanadium sulfate aqueous solutions 15, 35, 55, and 75 are used as the electrolytic solution of the redox flow battery 300, but when the discharge load of the redox flow battery 300 is large, When the charging current or discharging current is large, the current of the liquid circulation pumps 12, 32, 52, 72 is increased to 100% in step S15 so that the vanadium sulfate aqueous solution 15, 35, 55, 75 can function as an electrolyte. is circulated to
Of course, in step S14, when the charge/discharge load of the redox flow battery 300 is large and when it is small, it is divided into two. It is good, and you may make it correspond continuously.
Here, the time limit circuit 502 can be the circuit of steps S24 to S52, that is, the voltage adjustment circuit 503 described above.

That is, the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, and 75 of the present embodiment as the electrolyte is controlled as shown in the flowchart of FIG.
First, initialization is performed in step S20, and it is determined by the humidity sensor in step S21 whether or not the vanadium sulfate aqueous solution 15, 35, 55, 75 has leaked out. The positive and negative terminals of the redox flow battery 300 using 15, 35, 55, and 75 as electrolytes are opened to stop charging/discharging from the redox flow battery 300, and in step S23, the display 18 is flashed or one side or Repeat tumbles with red on both sides. That is, it complains of an abnormal stop state.
At this time, the color sensor 17 does not act at all. When the humidity sensor operates, the routine processing of steps S20 to S23 is repeatedly executed.

When it is determined in step S21 that the vanadium sulfate aqueous solution 15, 35, 55, 75 has not leaked from the humidity sensor, the color sensor 17 in step S24 causes the display 18 to light up numerical values or colors in step S25. 15, 35, 55, and 75 remaining discharge levels are detected. Specifically, the remaining discharge amount is calculated from the color detected by the color sensor 17, and the remaining discharge amount is displayed on the display 18 in step S26.
The indication that the display 18 lights up numerical values or colors is confirmation data during use of the redox flow battery 300 .
It is determined whether the value of the float sensor 100 in step S27 is within a predetermined range (the range sandwiched between a high value and a low value). , the rotational speed of the liquid circulation pump 12 is reduced.

Conversely, when the value of the float sensor 100 is lower than the predetermined liquid level, the rotational speeds of the liquid circulation pumps 12, 32, 52, 72 are increased. The liquid level is similarly controlled in steps S27 and S28. At this time, the liquid circulation pumps 12, 32, 52, 72 may be continuously variable, or may be speed-changeable in several stages.
In step S29, it is determined whether the output of the solar panel 301 is equal to or higher than the voltage Vmax, the output of the solar panel 301 is compared with the output of the redox flow battery 300, and the output of the redox flow battery 300 is higher than the output of the redox flow battery 300. When it is large, it is a suitable voltage for charging the Doxflow battery 300 .

When the electrolyte is "purple" and/or "yellow" in step S31, the movement speed of the electrolyte of the positive electrode side liquid circulation pumps 32, 72 and the negative electrode side liquid circulation pumps 12, 52 is slowed down or stopped. do. Therefore, when the electrolyte becomes "purple" and/or "yellow", it means that the charging is completed, so the moving speed of the electrolyte is slowed down or stopped.
After that, in step S33, it is determined whether or not the load of the redox flow battery 300 is light, and in steps S34 and S35, vanadium sulfate aqueous solutions 15, 35, 55, and 75 are used as the electrolytic solution of the redox flow battery 300. However, when the discharge load of the redox flow battery 300 is large, that is, when the charging current or discharging current of the redox flow battery 300 is large, the current of the liquid circulation pumps 12, 32, 52, 72 is increased to 100% in step S34. Then, the vanadium sulfate aqueous solutions 15, 35, 55 and 75 are circulated so as to function as an electrolytic solution.
Of course, in step S35, when the charge/discharge load of the redox flow battery 300 is large and when it is small, it is divided into two. and may be made to correspond continuously.

Here, in FIG. 18, the output of the solar panel 301 is input, and the voltage of the redox flow battery is set and input to the other. Therefore, the output of the comparison circuit 505 is "H" when the output of the solar panel 301 is higher than the voltage of the redox flow battery. Along with this, the redox flow battery charge characteristic 506, which is alternatively extracted from the charge characteristics stored in the memory of the CPU, determines the remaining amount of discharge 507 of the redox flow battery. When the electrolyte is "purple" and/or "yellow", the moving speed of the electrolyte in the positive electrode side liquid circulation pumps 32, 72 and the negative electrode side liquid circulation pumps 12, 52 is slowed down, or the charging operation is stopped. Stop.

In this way, the time limit circuit 502 can cope with the case where the circuit of steps S24 to S52 has not functioned for a long period of time. In addition, the voltage adjustment circuit 503 outputs "H" as the output of the comparison circuit 505 when the output of the solar panel 301 is higher than the voltage of the redox flow battery, thereby determining the charging characteristics from the matrix stored in the memory of the CPU. can be alternatively extracted and selected according to the value prepared for the redox flow battery charging characteristic 506 .

Here, when the set continuous stop time T of the positive electrode side liquid circulation pumps 32, 72 and the negative electrode side liquid circulation pumps 12, 52 is exceeded, the cell stacks 20, 60 may output does not rise steeply. The voltage adjustment circuit 503 causes the positive electrode side liquid circulation pumps 33 and 73 and the negative electrode side liquid circulation to flow through the positive electrode side charge/discharge circuits 33 and 73 and the negative electrode side charge/discharge circuits 13 and 53 at the timing of the continuous stop time T. The pumps 13, 53 are operated. As a result, even if some failure of the cell stacks 20 and 60 or failure of the cells occurs, the voltage regulation circuit 503 will make it less likely to be affected.
The voltage adjustment circuit 503 adjusts the movement speed of the electrolyte solution of the positive electrode side liquid circulation pumps 32, 72 and the negative electrode side liquid circulation pumps 12, 52 when the electrolyte solution is "purple" and/or "yellow". slow down and stop the charging operation.

In the redox flow battery 300 of the present embodiment, the voltage adjustment circuit 503 operates to control the positive electrode side liquid circulation pumps 32 and 72 and the negative electrode side liquid circulation pumps 12 and 12 when the electrolyte is "purple" and/or "yellow". Since the movement speed of the electrolyte solution of 52 is slowed down or stopped, when the electrolyte solution becomes "purple" and/or "yellow", it means that charging is completed. Since the supply of the liquid circulation pumps 32, 72 and the negative electrode side liquid circulation pumps 12, 52 is not necessary, that is, they simply add the charge/discharge load, they are removed from the load.

11, 31, 51, 71 electrolyte solution containers 12, 32, 52, 72 liquid circulation pumps 13, 33, 53, 73 circulation lines 13, 13a, 13b, 13c circulation lines 33, 33a, 33b, 33c circulation lines 15, 35, 55, 75 Vanadium sulfate aqueous solution 17 Color sensors 20, 60 Cell stack 21 Negative electrode side cell path 22 Positive electrode side cell path 44 Color detector 45 White LED
46 Optical fiber 50 Electrolyte distributor 52 Transparent circulation conduit 53 Inner circulation conduit 100 Float sensor 121 Center moving rod 123 Float 124 Reed switch 300 Redox flow battery 500 Battery housing body 501 Storage battery output circuit 502 Time limit circuit 503 Voltage adjustment circuit 505 Comparison Circuit 506 Redox flow battery charging characteristics 507 Remaining discharge

Claims (1)

a storage battery output circuit in which DC outputs of two or more cell stacks are connected in series;
a positive electrode-side electrolyte container and a negative electrode-side electrolyte container containing electrolytes having different characteristics;
a positive charge/discharge circuit and a negative charge/discharge circuit in which the flow of the electrolyte passing through the cell stack is in the same direction regardless of charging and discharging;
a positive electrode side liquid circulation pump and a negative electrode side liquid circulation pump that determine the flow of each of the electrolytes between the cell stack and the positive electrode side electrolyte container or between the cell stack and the negative electrode side electrolyte container;
a solar panel that converts the light energy of sunlight into electrical energy;
an inverter that converts the output of the solar panel from direct current to alternating current;
a voltage adjustment circuit for increasing the moving speed of the electrolyte in the positive electrode side liquid circulation pump and the negative electrode side liquid circulation pump when the output of the solar panel becomes higher than the output of the storage battery output circuit;
Equipped withdeath,
The electrolytic solution is an aqueous solution of vanadium sulfate,
The voltage adjustment circuit slows down the movement speed of the electrolyte solution of the positive electrode side liquid circulation pump and the negative electrode side liquid circulation pump when the charging completion is specified by detecting the color of the electrolyte solution by the color sensor, or or stop moving A redox flow battery characterized by:

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